Add version option to CLI

[edahlseng]

When using the Covalence CLI, I can't find a way to easily determine which version is running. My first instinct was to run bin/covalence --version but that just prints the help text (which also doesn't explain any option for getting the version). Is there any way to get this information from the CLI? If not, I think this could make a good addition.

[disaac]

@edahlseng You can execute the following with bin/covalence to output the gem version of covalence:

bin/covalence -OE bundle show covalence