RuboCop: Upgrade to 0.41.2, last to support Ruby1.9

[olleolleolle]

This PR:

• updates RuboCop to 0.41.2, last to support Ruby1.9
• sets TargetRubyVersion to 1.9
• sets a RuboCop exclusion on all the spec files which were Ruby-version-specific
• generates and includes a RuboCop TODO file with all the current lint failures

This sets us off on the journey of upgrading RuboCop and keeping up-to-date with style.

[olleolleolle]

Idea: Have RuboCop run in a separate "Build Stage", first, with a single Ruby version.

Example: https://travis-ci.org/egonSchiele/contracts.ruby/builds/279264498

See https://docs.travis-ci.com/user/build-stages/ for more.