Invalid Gemspec

[AxelTheGerman]

I know this isn't maintained anymore. But in case someone else is cloning/forking the repo and trying to build the gem, I was getting the following error:

$ gem build checkzilla.gemspec
ERROR:  While executing gem ... (Gem::InvalidSpecificationException)
    duplicate dependency on clamp (>= 0.3.0), (>= 0) use:
    add_runtime_dependency 'clamp', '>= 0.3.0', '>= 0'

Just remove line 16 from checkzilla.gem and it works like I charm.