Add git to cbmc-builder

alpine/Dockerfile

@@ -2,7 +2,7 @@ FROM alpine:3.5
 
 LABEL maintainer="DiffBlue Ltd."
 
-RUN apk add --no-cache gcc g++ make ccache bison flex perl-libwww bash
+RUN apk add --no-cache gcc g++ make ccache bison flex perl-libwww bash git
 
 # Will be mounted to source during run
 WORKDIR /cbmc

ubuntu/Dockerfile

@@ -4,7 +4,7 @@ LABEL maintainer="DiffBlue Ltd."
 
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
-      g++ gcc make ccache bison flex libwww-perl patch \
+      g++ gcc make ccache bison flex libwww-perl patch git \
 	  && rm -rf /var/lib/apt/lists/*
 
 # Will be mounted to source during run