Use python_version in requirements files for 2.6-specific stuff.

Author: gsnedders

requirements-install.sh

@@ -10,8 +10,6 @@ pip install -U -r requirements-test.txt
 if [[ $USE_OPTIONAL == "true" ]]; then
   if [[ $TRAVIS_PYTHON_VERSION == "pypy" || $TRAVIS_PYTHON_VERSION == "pypy3" ]]; then
     pip install -U -r requirements-optional.txt
-  elif [[ $TRAVIS_PYTHON_VERSION == "2.6" ]]; then
-    pip install -U -r requirements-optional-2.6.txt
   else
     pip install -U -r requirements-optional-cpython.txt
   fi

requirements-optional-2.6.txt

@@ -7,3 +7,7 @@ genshi
 # charade can be used as a fallback in case we are unable to determine
 # the encoding of a document.
 charade
+
+# Can be used to force attributes to be serialized in alphabetical
+# order.
+ordereddict ; python_version < '2.7'

requirements-optional.txt

@@ -3,5 +3,5 @@
 flake8
 pytest
 pytest-expect
-ordereddict # Python 2.6
 mock
+ordereddict ; python_version < '2.7'