Updating dockerfiles to allow for previewing of latest master and fixing local docker build so it works on osx

docker/dev/Dockerfile

@@ -13,8 +13,6 @@ ENV MYSQL_DATABASE=mattermost_test
 
 RUN groupadd -r mysql && useradd -r -g mysql mysql
 
-RUN apt-get update && apt-get install -y perl --no-install-recommends && rm -rf /var/lib/apt/lists/*
-
 RUN apt-key adv --keyserver pool.sks-keyservers.net --recv-keys A4A9406876FCBD3C456770C88C718D3B5072E1F5
 
 ENV MYSQL_MAJOR 5.6
@@ -24,7 +22,7 @@ RUN echo "deb http://repo.mysql.com/apt/debian/ wheezy mysql-${MYSQL_MAJOR}" > /
 
 RUN apt-get update \
 	&& export DEBIAN_FRONTEND=noninteractive \
-	&& apt-get -y install mysql-server \
+	&& apt-get -y install perl wget mysql-server \
 	&& rm -rf /var/lib/apt/lists/* \
 	&& rm -rf /var/lib/mysql && mkdir -p /var/lib/mysql
 
@@ -36,7 +34,8 @@ VOLUME /var/lib/mysql
 WORKDIR /mattermost
 
 # Copy over files
-ADD mattermost.tar.gz /
+RUN wget --no-check-certificate https://s3.amazonaws.com/mattermost-travis-master/mattermost.tar.gz
+RUN tar -zxvf mattermost.tar.gz --strip-components=1 && rm mattermost.tar.gz
 ADD config_docker.json /
 ADD docker-entry.sh /
 

docker/dev/Dockerrun.aws.json

@@ -1,7 +1,7 @@
 {
   "AWSEBDockerrunVersion": "1",
   "Image": {
-    "Name": "YOUR_DEV_INSTANCE_HERE",
+    "Name": "mattermost/platform:dev",
     "Update": "true"
   },
   "Ports": [