Sort packages in the base Dockerfile.

Dockerfile

@@ -2,11 +2,19 @@ FROM debian:jessie
 MAINTAINER Matt McCormick "matt.mccormick@kitware.com"
 
 RUN apt-get update && apt-get -y install \
+  automake \
+  autogen \
   bash \
-                        curl wget \
-                        pkg-config build-essential make automake autogen \
-                        tar xz-utils bzip2 gzip \
+  build-essential \
+  bzip2 \
+  curl \
   file \
+  gzip \
+  make \
+  pkg-config \
   rsync \
   sed \
-                        vim
+  tar \
+  vim \
+  wget \
+  xz-utils