resolves #155: remove needless checkouts on git-hack and git-extract
 Update development section of README
 resolves #165: git-sync restores deleted tracking branch
 resolves #123: smarter git-sync continue
 resolves #170: rake tasks
Update versions
Make ShellCheck actually work on Travis
Run Fuubar on Travis
Merge branch 'master' into kg-breaking-uncommitted-changes