* chore(deps): update dependency prettier to v1.8.0

* reformat

This PR adds support for 'AS' names in Dockerfiles. e.g. `FROM node:8 AS base`. It also adds logic to detect and ignore - for now - any image sources from custom registries.

Refactors file system of platforms and adds test to ensure GitHub and GitLab have same module.exports signatures.

Repository logic code has been rearranged for better logic and file separation.

Closes #654 

By searching for the *original* value, this caused problems if a tag gets updated multiple times in the same PR.

Closes #1050 hopefully for the last time

This PR refactors the onboarding PR logic into its own subdirectory and redesigns it to use plain markdown instead of html. Plain markdown in PR bodies is a requirement for adding VSTS Support ( #1049 ).

* refactor: move monorepos logic to npm manager

* fix test

Also clarify docs that encrypted config must be contained in renovate.json (i.e. not package.json).

This was necessary when attempting to use jest mock all

Renovate already detects PRs mistakenly closed during a certain time period when a bug was present. Now, it will rename those so that they are no longer detected and the ignore code does not have to remain indefinitely.

This allows parameter substitution to work correctly (undefined is replace, null is not).

Closes #1076

This refactor means that createPr now takes `labels` as a new parameter so that the GitLab API can include them with the MR creation request, so save one API call. This also fixes #985 as a result.

99% of the time we should not Renovate forked repositories. Previously, we skipped onboarding them unless a renovate.json was present. However, that meant that if someone forked a repository where the source was using Renovate, then the fork gets renovated automatically too. After this change, forked repositories need to set renovateFork=true in their renovate.json

Closes #940

BREAKING CHANGE: Forked repositories now need to configure renovateFork=true in renovate.json