use ruby-2.4.0 for travis
use ruby-2.4.0 for travis

enclose-io/compiler,lexor90/node-compiler,lexor90/node-compiler,lexor90/node-compiler,lexor90/node-compiler,lexor90/node-compiler,lexor90/node-compiler,enclose-io/compiler,lexor90/node-compiler,lexor90/node-compiler,lexor90/node-compiler,lexor90/node-compiler