Fix pylint breakage for kilo branch

Using test-requirements.txt to pin pylint to 1.4.4 and astroid to
less than 1.4.0, as newer versions break pylint. Doesn't apply to
liberty or newer, as they use constraints, which limit version.

It is expected that pylint will not be updated on this branch.

Change-Id: I417207a067b4f235ab6ddd479a5092505d63479f
Partial-Bug: #1521766

test-requirements.txt

@@ -3,10 +3,12 @@
 # process, which may cause wedges in the gate later.
 hacking<0.11,>=0.10.0
 
+astroid<1.4.0 # breaks pylint 1.4.4
 cliff<1.11.0,>=1.10.0 # Apache-2.0
 coverage>=3.6
 fixtures<1.3.0,>=0.3.14
 mock<1.1.0,>=1.0
+pylint==1.4.4 # GNU GPL v2
 python-subunit>=0.0.18
 requests-mock>=0.6.0 # Apache-2.0
 sphinx!=1.2.0,!=1.3b1,<1.3,>=1.1.2

tox.ini

@@ -73,9 +73,6 @@ sitepackages = True
 downloadcache = ~/cache/pip
 
 [testenv:pep8]
-deps =
-  {[testenv]deps}
-  pylint
 commands=
   # If it is easier to add a check via a shell script, consider adding it in this file
   sh ./tools/misc-sanity-checks.sh