* feat(universal): first implementation of universal support

* feat(demo): add universal docs, move useHash to env var

* refactor(demo): fix base href, move universal scripts to subdir

* perf(demo): add gzip compression

* test gcp deploy

* fix(tabs): use renderer instead native methods

removed empty bullet item in links

* chore(contributing): add CONTRIBUTING.md, remove unnecessary command in build manual

* chore(contribuing): add slack, new issue, new pr links, fix markup

* feat(docs): add versioning implementation

* refactor(docs): remove rimraf, simplify package.json commands

* feat(docs): add docs.archive to gh-pages script

* refactor(docs): remove else, reduce nesting

* feat(docs): docs versioning works with demo.serve

* refactor(docs): deploy and serve from gh-pages, add version check

* refactor(docs): clone/pull via js

* chore(build): simplifed archieve script

* chore(build): more tests

* Docs: add lib build for development steps

* chore(readme)

* chore(package): update dependencies

* docs(readme): add Greenkeeper badge

fixed a typo

* Include CDN instructions for Bootstrap 4

* chore(readme): added bs4 cdn instructions

* Fix Bootstrap 4 and card text #1637

Moved card class to a surrounding div so text formats correctly with Bootstrap 4

* Fix Bootstrap 4 and card text #1637

Moved card class to a surrounding div so text formats correctly with Bootstrap 4

* Added instructions for BS4

* Added instructions for BS4 setup with ng/cli

shows how to set up for bootstrap 4 in an angular-cli

* Links added to readme and getting-started for bs4 instructions

fixes #1343

closes #1270, closes #1188 

This commit updates all references of BS 3.0 from
3.3.* to 3.3.7 - as 3.3.7 was introduced in #783 PR
but no references in content have been udpated.

Thanks!