Move pep8 requirements in to test-requirements

We had these in tox.ini before to streamline pep8 (it didn't need
to actually install openstacksdk) But now that we're doing local
hacking checks, we have to install the code, which means this
optimization is bong. Put things back in test-requirements like
sane people. While doing that, remove readme, which isn't in
openstack/requirements and just let doc8 check it.

Change-Id: Id1860a1df33610ad7072c13ef9ee61395b785b94

lower-constraints.txt

@@ -2,6 +2,7 @@ appdirs==1.3.0
 coverage==4.0
 cryptography==2.1
 decorator==3.4.0
+doc8==0.8.0
 dogpile.cache==0.6.2
 extras==1.0.0
 fixtures==3.0.0
@@ -23,6 +24,7 @@ os-client-config==1.28.0
 os-service-types==1.2.0
 oslotest==3.2.0
 pbr==2.0.0
+Pygments==2.2.0
 python-mimeparse==1.6.0
 python-subunit==1.0.0
 PyYAML==3.12

test-requirements.txt

@@ -1,6 +1,8 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
+hacking>=1.0,<1.2 # Apache-2.0
+
 coverage!=4.4,>=4.0 # Apache-2.0
 extras>=1.0.0 # MIT
 fixtures>=3.0.0 # Apache-2.0/BSD
@@ -13,3 +15,5 @@ stestr>=1.0.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
+doc8>=0.8.0  # Apache-2.0
+Pygments>=2.2.0  # BSD license

tox.ini

@@ -39,15 +39,9 @@ commands = stestr --test-path ./openstack/tests/functional/{env:OPENSTACKSDK_TES
            stestr slowest
 
 [testenv:pep8]
-deps =
-    {[testenv]deps}
-    hacking
-    doc8
-    pygments
-    readme
 commands =
     flake8
-    doc8 doc/source
+    doc8 doc/source README.rst
 
 [hacking]
 local-check-factory = openstack._hacking.factory