Fails to parse gem versions surrounded by single quotes

[rhysm]

Hi,

I am using version 2.0.0 with the following dependency:

dependencies {
    gems 'rubygems:manticore:0.6.4'
}

This throws the following exception when trying to parse the gem version:

exception thrown for request to /rubygems/manticore/0.6.4/ivy.xml
com.github.jrubygradle.api.gems.GemVersionException: ''~> 4.5.0'' does not look like a GEM version requirement
        at com.github.jrubygradle.api.gems.GemVersion.gemVersionFromGemRequirement(GemVersion.groovy:245)
        at com.github.jrubygradle.api.gems.GemVersion$_gemVersionsFromMultipleGemRequirements_closure1.doCall(GemVersion.groovy:161)

The manticore.gemspec has single quotes around the version numbers in the jar requirements.

Should the quotes be removed from the gemspec source or should this project add support for parsing these version strings?

Thanks.