Allow to merge with --ff-only option
Merge pull request #427 from lzap/no-ff-option

Allow to merge with --ff-only option
Better timeouts in completion tests

- Increase timeouts to 3 seconds
- Implement waiting for completion in a way that it detects when pane
  contents have changed instead of waiting for a fixed amount every time.

Hopefully fixes failures such as:
- https://travis-ci.org/github/hub/jobs/14369618
- https://travis-ci.org/github/hub/jobs/14369403
Merge branch 'completion-timeout'
Use `noecho` method for password prompt if available

It will be available on Ruby >= 1.9
Merge branch 'stuartnelson3-master'

Closes #418
Fix typo in installation instructions

[ci skip]
Merge branch 'master' of ssh://github.com/github/hub