add chrome for testing support

fixes madnificent#26

Dockerfile

@@ -17,4 +17,22 @@ RUN apt-get update && apt-get -y install yarn
 # Install ember-cli
 RUN npm install -g [email protected]
 
+# 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
+
 WORKDIR /app