Removed ruby_version_is from UnboundMethod specs.
Removed ruby_version_is from Time specs.
Removed ruby_version_is from Thread specs.
Removed ruby_version_is from Symbol specs.
Removed ruby_version_is from Struct specs.
Removed ruby_version_is from String specs.
Removed ruby_version_is from Signal specs.
Removed ruby_version_is from Regexp specs.
Removed ruby_version_is from Rational specs.
Removed ruby_version_is from Range specs.
Removed ruby_version_is from command line specs.
Removed ruby_version_is from Random specs.
Removed ruby_version_is from Process specs.
Removed ruby_version_is from Proc specs.
Revert "Updated Hash#reject specs."

This reverts commit 834444304a68835d4cf38c662038c57f5040588f.

See
https://www.ruby-lang.org/en/news/2014/03/10/regression-of-hash-reject-in-ruby-2-1-1/
Fixed require paths for Proc specs.