DevTools updates.
Merge branch 'master', remote branch 'upstream/master'
Merge branch 'master' of https://github.com/google/WebFundamentals into devtools-updates
Merge pull request #721 from umaar/devtools-updates

Devtools updates
Fixes #720 and Fixes #719 and also a number of other links
Merge branch 'master' of github.com:google/WebFundamentals
Devsite needs links scheme relative for resources
Parse samples with liquid, inject site var

@paulkinlan @agektmr take a look at this change.
We now parse templates as liquid, and make the site config var available, so you should be able to add any new config requires.
I have some concern this might conflict with any {{}} style templates currently in use - I coudn't see any, but worth a second pair of eyes.
Use .ruby-version and allow for overrides

Implements the canonical solution, suggested in
[this](https://stackoverflow.com/questions/16087120/should-i-check-in-ruby-gemset-and-or-ruby-version/16738020#16738020) Stack Overflow answer by the maintainer of RVM.

- Add specific ruby version as a dotfile
- Allow any ruby gemset name
- Allow override of .ruby-version and .ruby-gemset using .rvmrc
Moves .ruby-version and .ruby-gemset to the root.

They need to be placed in the same directory as the command
```sh
make server
```
Would be run from.

See discussion
[here](https://github.com/google/WebFundamentals/pull/694).

Closes #693
Closes #694
Adds contributors image for jbnicolai
Adds jbnicolai to _contributors.yaml.

Happy to be added to the contributors page :smile:.

Closes #723.
Merge remote-tracking branch 'upstream/master'
Merge pull request #727 from jbnicolai/issue/723

Adds jbnicolai to the contributors page
Merge pull request #724 from jbnicolai/issue/693

Use .ruby-version and allow for overrides.
Update _contributors.yaml

Changing a role for jbnicolai
Updating contributor page to list external contribs
Updating human.txt to add in contribs
Fix issue #731
Merge pull request #732 from jacquerie/issue-731

Issue 731