update more images to use alpine

Signed-off-by: Jessica Frazelle <princess@docker.com>

rainbowstream/Dockerfile

@@ -7,17 +7,20 @@
 #	--name rainbowstream \
 #	jess/rainbowstream
 #
-FROM python:latest
+FROM alpine:latest
 MAINTAINER Jessica Frazelle <jess@docker.com>
 
-RUN apt-get update && apt-get install -y \
-	libjpeg-dev \
-	libfreetype6 \
-	libfreetype6-dev \
-	zlib1g-dev \
-	--no-install-recommends \
-	&& rm -rf /var/lib/apt/lists/*
-
-RUN pip install rainbowstream
+RUN apk update && apk add \
+	build-base \
+	ca-certificates \
+	freetype \
+	freetype-dev \
+	openjpeg-dev \
+	python \
+	python-dev \
+	py-pip \
+	zlib-dev \
+	&& rm -rf /var/cache/apk/* \
+	&& pip install rainbowstream
 
 ENTRYPOINT [ "rainbowstream" ]