Add Dockerfile based on alpine python 2.7.14 (#44)

Author: MattSurabian

Dockerfile

@@ -0,0 +1,7 @@
+
+FROM python:2.7.14-alpine3.7
+
+COPY ./requirements.txt /mnt/dynamodump/requirements.txt
+COPY ./dynamodump.py /usr/local/bin/dynamodump
+
+RUN pip install -r /mnt/dynamodump/requirements.txt