Add bash scripts to help install and test

Add useful bash scripts to install and run pytest
for all versions of Python that I'm currently running
on my BeagleBone.

"python" package in Debian 9.2:
Python 2.7.13

"python3" package in Debian 9.2:
Python 3.5.3

compiled from source by myself on a beaglebone:
Python 3.6.3

Example usage:
debian@beaglebone:~/ssh/adafruit-beaglebone-io-python$ sudo ./install_all_python_versions.sh && ./pytest_all_versions.sh

Signed-off-by: Drew Fustini <drew@pdp7.com>

Author: pdp7

install_all_python_versions.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+# useful for testing changes against all versions of python
+make clean
+echo "Install Python 2.7"
+python2.7 ./setup.py install
+echo "Install Python 3.5"
+python3.5 ./setup.py install
+echo "Install Python 3.6"
+python3.6 ./setup.py install

pytest_all_versions.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+# useful for testing changes against all versions of python
+
+cd test
+echo "Testing Python 2.7"
+python2.7 -mpytest
+echo "Testing Python 3.5"
+python3.5 -mpytest
+echo "Testing Python 3.6"
+python3.6 -mpytest
+cd ..