Added Dockerfile. (#240)

* Added Dockerfile.

* Changes as requested by @japesinator.

Dockerfile

@@ -0,0 +1,15 @@
+FROM ubuntu:16.04
+MAINTAINER JP Smith
+
+RUN apt-get -y update && \
+	DEBIAN_FRONTEND=noninteractive apt-get -y install z3 python-pip git && \
+	git clone https://github.com/trailofbits/manticore.git && \
+	cd manticore && \
+	pip install .
+
+RUN useradd -m manticore
+USER manticore
+WORKDIR /home/manticore
+ENV HOME /home/manticore
+
+CMD ["/bin/bash"]