Don't try to kill if pid is nil
Forward signals to running process group

If a command spawns child processes within the same process group, then
they also need to receive the signals.
fix indent
Ignore vendor/gems in test app
add travis CI status image
Merge pull request #43 from senny/travis_ci_status

add travis CI status image
configuration option to sepcify the rails root (gets engines working)
replace Pathname `+` with `join` in the README
the watcher is stale when a file is removed. closes #18
Merge pull request #44 from senny/watcher_handles_removed_files

the watcher is stale when a file is removed
Merge pull request #37 from senny/custom_application_root

Provide a configuration option to set the rails root