At least for ansible 2.0.0.1 the command `ansible-galaxy --help` is inappropriate for testing if ansible is installed, as it yields an error:
```
vagrant@vagrant-ubuntu-trusty-64:~$ ansible-galaxy --help && echo "OK"
Usage: ansible-galaxy [delete|import|info|init|install|list|login|remove|search|setup] [--help] [options] ...
Options:
-h, --help show this help message and exit
-v, --verbose verbose mode (-vvv for more, -vvvv to enable connection
debugging)
--version show program's version number and exit
ERROR! Missing required action
```
9dbdb9397a