Update Dockerfile, add mingw

Dockerfile

@@ -56,6 +56,8 @@ RUN apt-get upgrade -y \
 		nasm \
 		python2.7 \
 		python-pip \
+		g++-mingw-w64 \
+		gcc-mingw-w64 \
 	&& rm -rf /var/lib/apt/lists/*
 
 RUN echo "###### Ubuntu Main Repos" > /etc/apt/sources.list && \