CLC-4595 - Update gems - angular

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
CLC-4595 - Update gems - autoprefixer-rails

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
CLC-4595 - Update gems - icalendar

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
CLC-4595 - Update gems - ng-annotate

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
CLC-4595 - Update gems - secure_headers

https://github.com/twitter/secureheaders/releases

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
CLC-4595 - Update gems - signet

https://gemnasium.com/gems/signet

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
CLC-4595 - Update gems - page-object

https://gemnasium.com/gems/page-object

https://jira.ets.berkeley.edu/jira/browse/CLC-4595
Merge pull request #3190 from christianv/CLC-4595

CLC-4595 - Update gems - page-object / signet / secure_headers / ng-annotate / icalendar / autoprefixer-rails / angular