Revert "Disable memcached travis tests until appneta/oboe-ruby#52 is fixed."
Revert "Disable memcached travis tests until appneta/oboe-ruby#52 is fixed."

This reverts commit 06ba0ef6a9253b3f7b84e6a3afc742e5b71a010e.

boyang-li/oboe-ruby,tlunter/oboe-ruby,boyang-li/oboe-ruby,tlunter/oboe-ruby,appneta/ruby-traceview,appneta/ruby-traceview,appneta/ruby-traceview,boyang-li/oboe-ruby,tlunter/oboe-ruby,tlunter/oboe-ruby,boyang-li/oboe-ruby,appneta/ruby-traceview