Handle rubygems failure

[stuartmg]

This PR rescues any errors that occur while fetching the gem info from rubygems.org. This information is only used to create links to the gem homepage, documentation, and source. An error during this lookup should not prevent the report from being generated.

This also updates the version of a number of dependencies so that it can be more easily used by other projects.

Finally, this removes the Gemfile.lock file from the repository and ignores it.

This PR addresses #35 and #36.