Travis: launch sam tests only with python2.7

* Waiting for PR tuttleofx#524 to switch to python3.4.
* Currently there is an error with python3.2:
"sudo pip3 install clint argcomplete
/usr/local/lib/python3.2/dist-packages/pip-8.1.0-py3.2.egg/pip/_vendor/pkg_resources/__init__.py:87:
UserWarning: Support for Python 3.0-3.2 has been dropped. Future
versions will fail here.".

Author: Clement Champetier

tools/travis/install_dependencies.sh

@@ -11,7 +11,8 @@ if [[ ${TRAVIS_OS_NAME} == "linux" ]]; then
     if [[ ${PYTHON_VERSION} == "2.7" ]]; then
         pip install --user clint argcomplete
     elif [[ ${PYTHON_VERSION} == "3.2" ]]; then
-        pip3 install --user clint argcomplete
+        # easy_install3 pip --prefix=$HOME/local
+        # pip3 install --user clint argcomplete
     fi
 
     # Use TRAVIS_JOB_ID to detect that we are in travis.

tools/travis/launch_tests.sh

@@ -29,4 +29,6 @@ cd ${TUTTLEOFX_BUILD}
 make run_tests
 
 # sam tests
-${TRAVIS_BUILD_DIR}/applications/test/samCommands.sh
+if [[ ${PYTHON_VERSION} == "2.7" ]]; then
+    ${TRAVIS_BUILD_DIR}/applications/test/samCommands.sh
+fi