Improve tox.ini, install py26 for travis.

Signed-off-by: Dan O'Reilly <oreilldf@gmail.com>
diff --git a/python/tox.ini b/python/tox.ini
index 4a994b6..ebe7545 100644
--- a/python/tox.ini
+++ b/python/tox.ini
@@ -2,17 +2,20 @@
 envlist =
     # Py3 tests currently fail because of text handling issues,
     # So only test py26/py27 for now.
-    #py26,py27,py33,py34
-    py26,py27
+    #py{26,27,33,34}-{cpp,python}
+    py{26,27}-{cpp,python}
 
 [testenv]
-usedevelop = true
 setenv =
-    LD_LIBRARY_PATH={toxinidir}/../src/.libs
+    cpp: LD_LIBRARY_PATH={toxinidir}/../src/.libs
+    cpp: PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp
 commands =
     python setup.py -q build_py
-    python setup.py -q build {posargs}
-    python setup.py -q test -q {posargs}
-    pip install --install-option {posargs: -q} .
+    python: python setup.py -q build
+    cpp: python setup.py -q build --cpp_implementation
+    python: python setup.py -q test -q
+    cpp: python setup.py -q test -q --cpp_implementation
 deps =
     six
+    py26: ordereddict
+    py26: unittest2
diff --git a/travis.sh b/travis.sh
index b53b960..e76d83b 100755
--- a/travis.sh
+++ b/travis.sh
@@ -111,21 +111,30 @@
   build_javanano
 }
 
+internal_install_python_deps() {
+  sudo pip install tox
+  sudo apt-get install -y python-software-properties # for apt-add-repository
+  sudo apt-add-repository -y ppa:fkrull/deadsnakes
+  sudo apt-get update -qq
+  sudo apt-get install -y python2.6 python2.6-dev
+}
+
+
 build_python() {
   internal_build_cpp
-  sudo pip install tox
+  internal_install_python_deps
   cd python
-  tox
+  tox -e py26-python,py27-python
   cd ..
 }
 
 build_python_cpp() {
   internal_build_cpp
-  sudo pip install tox
-  export   LD_LIBRARY_PATH=../src/.libs # for Linux
+  internal_install_python_deps
+  export LD_LIBRARY_PATH=../src/.libs # for Linux
   export DYLD_LIBRARY_PATH=../src/.libs # for OS X
   cd python
-  tox -- --cpp_implementation
+  tox -e py26-cpp,py27-cpp
   cd ..
 }