Add basic HookSpecificCheck coverage
Add basic HookSpecificCheck coverage

Not testing the git-specific (e.g. staged files) stuff yet, but sanity
checking commit messages.

Change-Id: I07298d2615365796906c37b8f6d469a78840f0ec
Reviewed-on: https://gerrit.causes.com/22959
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@causes.com>
Reviewed-by: Joe Lencioni <1dd72cf724deaab5db236f616560fc7067b734e1@causes.com>

oxocode/overcommit,blech75/overcommit,oxocode/overcommit,TheSooth/overcommit,blech75/overcommit,gnagel/overcommit,TheSooth/overcommit,gnagel/overcommit