Remove gemspec / dependency present check in Bundler DSL
Remove gemspec / dependency present check in Bundler DSL

These are no longer required since neither instance variable will
be nil, and the utils rejects any empty strings:

https://github.com/thoughtbot/appraisal/blob/979bd941dca752639e45a29d1bf42960a01dba3e/lib/appraisal/utils.rb#L43

thoughtbot/appraisal