add chrome for testing support

fixes #26

templates/Dockerfile

@@ -17,3 +17,21 @@ RUN apt-get update && apt-get -y install yarn
 RUN npm install -g ember-cli@@EMBER_VERSION
 
 WORKDIR /app
+
+# install chrome for default testem config
+RUN \
+    apt-get update &&\
+    apt-get install -y \
+        apt-transport-https \
+        gnupg \
+        --no-install-recommends &&\
+  curl -sSL https://dl.google.com/linux/linux_signing_key.pub | apt-key add - &&\
+  echo "deb [arch=amd64] https://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google-chrome.list &&\
+  apt-get update &&\
+  apt-get install -y \
+      google-chrome-stable \
+      --no-install-recommends
+
+# tweak chrome to run with --no-sandbox option
+RUN \
+  sed -i 's/"$@"/--no-sandbox "$@"/g' /opt/google/chrome/google-chrome