add rpm spec file
Merge pull request #3 from jmontleon/add-rpm-spec

add rpm spec file
getting an `uninitialized constant HammerCLIForemanTasks::VERSION`

in a jenkins job when tito attempts to build the gem and srpm
Merge pull request #4 from komidore64/happy-gemspec

getting an `uninitialized constant HammerCLIForemanTasks::VERSION`