fetch all remote urls, including pushurl

Fixes #41
`--shared` is now false by default in `deploy setup`

Most deploys are done with a dedicated user, so we will avoid messing
around with permissions and the sticky bit if not needed. People who are
deploying in a shared environment (multiple deploying users) should pass
`--shared` explicitly during setup.

Fixes #25
lock Thor to version that was known to work

Avoids erikhuda/thor#234, closes #31
remove dead code
execute deploy hooks synchronously and not in background

This means `git push` will now block and receive deploy log output until
all hooks have finished executing, same as Heroku.
README facelift
lies!

References 64d75f3
improve filtering unversioned files in gemspec: don't.
MIT to gemspec
RIP rip
add RSpec to bundle
add `rerun` task to retry a failed deploy callback

fixes #32
improve `rollback` task
document all hooks, tasks
v0.6.0
enable Travis CI
fix reading git remote URLs on Ruby 1.8.7

Strip extra whitespace in the end because URI.parse chokes on it.

Fixes #49, closes #50, closes #51
v0.6.1
doc typo

[ci skip]