chore(stark-all): remove greenkeeper-lockfile and obsolete RxJS artifacts. Ban imports from '@angular/material' and 'lodash' root entry points

[christophercr]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NationalBankBelgium/stark/blob/master/CONTRIBUTING.md#-commit-message-guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[X] Build related changes
[X] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: #585

What is the new behavior?

• Removed rxPaths() mapping since it is not needed anymore with RxJS 6 and Webpack 4+ (see Make rxjs a side-effect free package (for webpack v4) ReactiveX/rxjs#3212 and Should libraries that depend on rxjs use path-mappings/tree shaking? ReactiveX/rxjs#3227).
• Removed obsolete rxjs-compat dependency since we no longer have deps using RxJS lower than 5
• Refined Angular Material imports to improve tree-shaking in prod builds (see Tree-shaking for production build is not working properly angular/components#4137)
• Set tslint import-blacklist rule to avoid imports from @angular/material and lodash root entry point
• Removed greenkeeper-lockfile since Greenkeeper has now native support for lockfile's

Does this PR introduce a breaking change?

[ ] Yes
[X] No

[coveralls]

Coverage decreased (-0.02%) to 91.709% when pulling 82bf7ab on christophercr:feature/build-enhancements into 688111d on NationalBankBelgium:master.