change site title
remove posts from gitignore for heroku
.git heroku hack, tests for github_hook.rb

Heroku's slug generation mechanism removes .git files; write a script
for pushing to Heroku that puts the caching info from 'git log' into a
text file and modify github_hook.rb to use that file. Also write tests
for github_hook.rb.
add /posts/* to .gitignore