added some docker stuff

FlippR-Driver/cross-docker/Dockerfile

@@ -0,0 +1,12 @@
+FROM ubuntu:latest
+
+RUN apt update \
+    && apt install -y git rsync cmake gcc-7-arm-linux-gnueabihf g++-7-arm-linux-gnueabihf 
+    
+RUN cd ~ \
+    && mkdir raspberrypi \
+    && cd raspberrypi \
+    && mkdir rootfs
+    
+COPY lib /root/raspberrypi/rootfs/
+COPY usr /root/raspberrypi/rootfs/

FlippR-Driver/cross-docker/build-docker.sh

@@ -0,0 +1,3 @@
+#! /bin/bash
+
+docker build -t raspberrycross .

FlippR-Driver/cross-docker/docker-bash.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+docker run -v $(pwd):/root/flippr -it raspberrycross:latest bash