Use slim docker image + only print >warning on npm i (#703)

TylerBrock · flovilmart · commit 3118cd38314d · 2017-05-22T11:18:56.000-04:00
diff --git a/Dockerfile b/Dockerfile
@@ -1,4 +1,5 @@
-FROM node:4.4.2
+FROM node:argon-slim
+ENV NPM_CONFIG_LOGLEVEL error
 WORKDIR /src
 ADD . /src
 RUN cd /src \
