Disable TravisCI for Node v0.6.
Disable TravisCI for Node v0.6.

Regenerator still works on v0.6, `npm install` just doesn't work so well.

kittens/regenerator,sebmck/regenerator,liviuignat/regenerator,facebook/regenerator,kittens/regenerator,rafaelstz/regenerator,sebmck/regenerator,juliocanares/regenerator,RReverser/js-goto-transpiler,Jericho25/regenerator,rafaelstz/regenerator,facebook/regenerator,facebook/regenerator,juliocanares/regenerator,Jericho25/regenerator,liviuignat/regenerator,RReverser/js-goto-transpiler