update go version to 1.5.3 in dockerfile and cleanup

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

script/test_Dockerfile

@@ -1,19 +1,19 @@
-FROM golang:1.4
+FROM golang:1.5.3
 
 RUN echo "deb http://ftp.us.debian.org/debian testing main contrib" >> /etc/apt/sources.list
 RUN apt-get update && apt-get install -y \
-	curl \
     build-essential \
+    curl \
+    iptables \
     libaio-dev \
     libcap-dev \
     libprotobuf-dev \
     libprotobuf-c0-dev \
+    libseccomp2 \
+    libseccomp-dev \
     protobuf-c-compiler \
     protobuf-compiler \
     python-minimal \
-	iptables \
-	libseccomp2 \
-	libseccomp-dev \
     --no-install-recommends
 
 # install criu