fix: fixed node version for CI (#365)

Arfey · jettify · commit 1f13da07af2e · 2018-05-05T20:54:41.000+03:00
diff --git a/.travis.yml b/.travis.yml
@@ -7,8 +7,8 @@ services:
     - docker
 
 before_install:
-    - nvm install node
-    - nvm use node
+    - nvm install 9.9.0
+    - nvm use 9.9.0
     - npm i -g yarn@0.16.1
 
 install:
