Rakefile default task should be to run specs

Fixes #5
Memoize Hipchat#user

Fixes #7
Stub git config user.email
Merge pull request #6 from bmarini/default-task

Rakefile default task should be to run specs
Merge pull request #9 from bmarini/portable-specs

Stub git config user.email
Merge pull request #8 from bmarini/memoize-hipchat-user

Memoize Hipchat#user
Merge branch 'master' into git-config

Conflicts:
	spec/git-deploy/hipchat_spec.rb
Get the user email in the git config middleware