Update gem description

SCSS lint is now configurable, so use that as an adjective instead of
"opinionated".

Change-Id: I82b4004b7d1c84bedaf08220af31158b4cb7b397
Reviewed-on: http://gerrit.causes.com/36034
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
Add Overcommit configuration file

Enable Gerrit change ID hook.

Change-Id: I5d7fa938a51b63127f40154a2051c51c4e21aba5
Reviewed-on: http://gerrit.causes.com/36035
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>