This PR adds support for bazel WORKSPACE package files, as suggested https://github.com/alexeagle/angular-bazel-example/issues/17#issuecomment-349167982

Renovate will:
1. Detect `WORKSPACE` files anywhere in the repository
2. Look for all `git_repository()` sections in the file
3. Extract any dependencies with name, remote and tag values
4. Look up any dependencies that (a) have a github https remote, and (b) a valid semver as tag
5. Update the tag to the latest available

This PR adds support for renovating the `node_js` versions in `.travis.yml` configuration files. Important notes:
- Functionality is disabled by default and hence opt-in via configuration
- Added a new manager type `node` because it is anticipated to support more than just Travis in future, with mostly unified logic
- Added the config option "policy" with supported values: lts, active, current, lts_latest and lts_active
- Policy is actually an array, to allow additive combining, e.g. `["lts_latest", "current"]`
- Actual node versions are *hardcoded*. There is no perfect metadata source for this and they change infrequently enough that it is definitely not a problem for now (next change will be in April 2018)
- If node versions need updating, they are listed from newest to oldest
- Replacing function attempts to detect the indention (spacing) in file and use that

To enable, configure `node.enabled=true` and optionally `node.policy=["<policy>"]` if you want something other than `lts`.

Closes #1208

Remove original getFile, getFileContent, and getFileJson and replace with getFile (which used to be getFileContent.. shortened now for convenience). Also remove unused getSubdirectories functions.

This is instead of autodetecting lib or app during onbiarding. This means some package files might be all pinned while others in the same monorepo can be not. This also simplifies the onboarding logic.

docker and npm

It appears that writing the existing lockfile before regenerating a new one can help speed some resolutions up.

Closes #815

* chore(deps): update dependency eslint-config-airbnb-base to v12.0.0

* fix lint

This feature adds initial support for renovating Dockerfiles. Renovate now:
- Detects all `Dockerfile`s in repo
- Searches for `FROM x` in first non-comment line, breaks x into image, tag, digest
- Queries public Docker registry for image:tag combination to find latest digest
- Patches Dockerfile if necessary
- Creates branches/PRs as like with npm

Closes #795 

* fix eslint configuration

* run eslint fix

This feature adds support for renovating Meteor's `package.js` files. Meteor config is disabled by default so must be manually enabled to work. If enabled, Renovate uses GitHub's search API to look for any files named `package.js` that include the text `Npm.depends`. If so then the file is parsed using Regex to extract its dependencies and check them for updates.

Closes #785 

Renovate config can now support the fields `npmToken`, `npmrc` and `yarnrc`. `npmrc` and `yarnrc` (note no `.` prefix) can be used as an alternative to checking the respective files into the repo and have the same effect. `npmToken` is a shorter alternative and allows for just the npm token to be added, defaulting to the public npm registry.

This feature adds explicit support for correctly generating the yarn.lock file for workspaces. Specifically, it means that the yarn.lock in the root directory is regenerated whenever *any* package.json is modified. Previously lock files were only every updated if its corresponding package.json changes, but that is not the way yarn workspaces works.

Closes #473

This is a major refactor of branch code to prepare for Yarn workspaces plus creating PRs for branches with failing lockfiles. Marked as "feature" to cause a minor version bump due to the moderate chance of accidentally breaking something.

Repository initialisation is refactored so that all package files and their content is retrieved up-front before an renovating begins. This allows us to know both how many package files as well as determine if there is renovate json in a package.json before triggering the onboarding PR.

Closes #634

Now no need to detect at onboarding time. Also suggests removing setting in migration if it is already the same value.

Closes #528

Links to open issue about workspaces.

Closes #601

Closes #226 

depTypes configuration is now refactored from being an array of strings/objects to having each type of dep (`dependencies`, `devDependencies`, `optionalDependencies`, `peerDependencies`) be a first class object in the namespace. The "old" way of configuring is still supported but is transformed using a migrateConfig script. Later, PRs will be raised to impacted repositories to suggest the new config.

This PR adds detection and log warnings for the following config validation errors:
- Unknown config option (e.g misspelling of a valid config option)
- Config option is a wrong type (e.g. string instead of boolean)

It does *not* propagate this warning to the user (i.e. in onboarding or PRs) yet due to the high chance that we'll find a false negative. I will watch logs for a week or so and then once happy with results will activate user-visible warnings via #556.

Closes #548, Closes #555

It’s now possible to set `RENOVATE_LOCK_FILE_MAINTENANCE={}` in env to disable lock file maintenance.

Closes #515

This removes the need to JSON.stringify() objects in logs. Default bunyan fields plus our custom meta fields are stripped out, and everything else is stringified in the details field.

Closes #498

Renovate will now "maintain" npm@5's `package-lock.json` files on the same schedule as existing `yarn.lock` maintenance.

Closes #470

Schedule logic has been refactored to enable the pruning of all orphan branches. 
Now, schedules aren't checked at package-time, instead package upgrades are queued regardless of schedule. 
At branch time, it is checked whether the *branch* is scheduled and then the branch is not created/updated if it's off-schedule.
This enables the repository worker to know all possible branches and hence be able to determine which remaining branches in the repository are "orphans" to be deleted.

Closes #428, Closes #426 

baseBranch is now used when computing the onboarding description in 'Configure Renovate' PR.

Errors in PRs are expanded to include:
- If renovate.json parsing fails
- If an empty or unparseable package.json was found

Closes #435 

This feature now allows a custom schedule to be defined for lock file maintenance. It is now enabled by default but runs only before 5m on Sundays. Closes #399

BREAKING CHANGE: lock file maintenance is enabled by default.
Rules will apply to both yarn and npm (npm is yet to be implemented however). Existing mainainYarn* variables are removed and replaced by new lockFileMaintenance object.

* Move yarn and npm helpers into branch worker

* Fix name

* Move package-json helper

* Update name

* Move changelog

* Move github-app

* Remove unused platform

* Move logger

* Fix lint