Drop Python 2.6 support, our test dependencies no longer support it

.travis.yml

@@ -1,6 +1,5 @@
 language: python
 python:
-  - "2.6"
   - "2.7"
   - "3.3"
   - "3.4"
@@ -9,9 +8,8 @@ python:
   - "pypy3"
 
 install:
-  # note: Twisted doesn't support Python 2.6 any more
   - |
-    if [[ $TRAVIS_PYTHON_VERSION == pypy3 || $TRAVIS_PYTHON_VERSION == 3.* || $TRAVIS_PYTHON_VERSION == 2.6 ]]; then
+    if [[ $TRAVIS_PYTHON_VERSION == pypy3 || $TRAVIS_PYTHON_VERSION == 3.* ]]; then
       pip install -r requirements-py3-devel.txt
     else
       pip install -r requirements-py2-devel.txt

docs/index.rst

@@ -51,7 +51,6 @@ Compatibility
 
 Tested to work with:
 
-- python 2.6
 - python 2.7
 - python 3.3
 - python 3.4

tests/run_tests.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 PYTHON_IMPLEMENTATIONS=${PYTHON_IMPLEMENTATIONS:-"python pypy jython"}
-python_VERSIONS=${PYTHON_VERSIONS:-"2.6 2.7 3.3 3.4 3.5"}
+python_VERSIONS=${PYTHON_VERSIONS:-"2.7 3.3 3.4 3.5"}
 pypy_VERSIONS=${PYPY_VERSIONS:-"nover 3"}
 jython_VERSIONS=${JYTHON_VERSIONS:-"nover"}
 
@@ -40,7 +40,6 @@ for pyexec in $PYEXECS; do
   if [[ "$RUNNERS" =~ nose ]]; then
     if $pyexec -c 'import nose' 2>/dev/null; then
       echo nose for $pyexec
-      # can't use "-m nose" with 2.6: python2.6: nose is a package and cannot be directly executed
       $pyexec -m nose.__main__ $TEST_PATH/flexmock_nose_test.py
       [[ $? -ne 0 ]] && EXIT_CODE=1
     else