Combine to a single RUN command and clean cache afterwards

Author: BenHall

src/DockerBase/Dockerfile

@@ -5,9 +5,7 @@ MAINTAINER GitTools Maintainers <[email protected]>
 # Wheezy doesn't support glibc 2.15 which libgit2sharp requires
 # So we are going to install mono on ubuntu instead
 RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
-RUN apt-get update
-RUN apt-get install libcurl3 tzdata unzip curl git-all -y
-RUN echo "deb http://download.mono-project.com/repo/debian wheezy main" | tee /etc/apt/sources.list.d/mono-xamarin.list
-RUN apt-get update
-RUN apt-get install mono-complete -y
+RUN echo "deb http://download.mono-project.com/repo/debian wheezy main" | tee /etc/apt/sources.list
+.d/mono-xamarin.list
+RUN apt-get update && apt-get install libcurl3 tzdata unzip curl git-all mono-complete -y && apt-get -yqq clean
 RUN cp /usr/share/zoneinfo/GMT /etc/localtime