docs: update to Angular 1.6.7

[Splaktar]

PR Checklist

Please check that your PR fulfills the following requirements:

• The commit message follows our 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
[ ] CI related changes
[ ] Documentation content changes
[ ] Infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Documentation site is running Angular 1.5.5. This is partially due to full AngularJS 1.6.x support not being ready until AngularJS Material 1.1.4.

Issue Number:
N/A

What is the new behavior?

Documentation site is running Angular 1.6.7. All AngularJS 1.6.x issues are closed. Nice to jump up to this version before AngularJS 1.7.x is released as well. If there are any undiscovered AngularJS 1.6.x related issues, hopefully they will be evident and easy to reproduce in the docs.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

N/A