Renames currentVersion to currentValue, newVersion to newValue, newVersionMajor to newMajor, and newVersionMinor to newMinor.

This PR refactors `branchName`, `commitMessage` and `prTitle` so that they are more easily editable and hopefully more understandable. By breaking each up into subsections, users can modify one part without needing to copy/paste the entire string.

Directly editing any of these fields will now be deprecated and a warning issued.

Closes #1652

Closes #1652

Updates travis config and logic to use same variables as for other managers. This fixes the onboarding PR.

Fixes #1551

This PR adds the capability to renovate more than one base branch at a time. For instance, a project may have their released `3.x` version on `master`, while an upcoming `4.x` is being prepared using branch `next`. `4.x` might have a quite different set of dependencies (e.g. some removed or some added) so it's not appropriate to only target `master` and keep rebasing, as it will get messy. Instead, it's necessary to target both `master` and `next` to keep both updated.

Closes #1279

By stripping ‘types/ from the branch name, package x and @types/x then become automatically combined in the same PR. We then massage it a little to ensure the decription for the non-types package is used, and a note added saying that types is included.

Closes #1365

Now, if every upgrade in a group has the same new version, then the PR title will include this version.

Closes #1332

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

* reformat

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

Closes #654