add Chart.js as vendor

http://www.chartjs.org
sync cached gems
Use a SQF grammar for SQF files

This produces better highlighting than using the C++ grammar.

The grammar is licensed under the Apache 2.0 license.
Merge pull request #1752 from github/sqf-grammar

Use a SQF grammar for SQF files
Switch to a better grammar for Bro

This grammar seems to be replacing the other ones out there and is
maintained by the Bro organization.
Merge pull request #1753 from github/better-bro-grammar

Switch to a better grammar for Bro
Chart JS is vendored
Fix RHTML's tm_scope

I missed this back in 9595e2ba7e63b584e2a32cdee3c86ad9ffccf261.
Merge pull request #1755 from github/fix-rhtml-scope

Fix RHTML's tm_scope
Test that all languages have grammars

This will make CI fail if someone adds a new language but neglects to
add a new grammar for it. This should make it easier for people to
review PRs, as CI will help them to make sure a new grammar gets added.

However, we currently support some languages that have no grammars, and
we may support more in the future. So you can explicitly mark the
language as having no grammar by setting `tm_scope: NONE` in
languages.yml.
Checking other case for Chart.jS
Merge pull request #1754 from github/chart-js

Chart js
Change NONE to none

NONE is a little shouty.
Add some docs for tm_scope
Merge pull request #1756 from github/test-for-grammars

Test that all languages have grammars