Update .travis.yml

Author: Widdershin

.travis.yml

@@ -1,11 +1,12 @@
-language: generic
+language: ruby
 before_script:
 - git submodule update --init --recursive
 - ./emsdk/emsdk install 1.38.46
 - ./emsdk/emsdk activate 1.38.46
 - source ./emsdk/emsdk_env.sh
 - make patch-mruby && make mruby-build
-- export PATH=mruby/build/host/bin:$PATH 
+- export PATH=mruby/build/host/bin:$PATH
+- npm install
 
 script:
-- make runtime
+- make