Add tox checkniceness,checksyntax for docs

* Add tox -e checkniceness and tox -e checksyntax to
make the docs almost perfect.
* Make tox -e docs task to call check* tasks as well
* Sanitize dependency install for separate tasks:
  - docs, do not install non related eggs from test-requirements
  - check*, install only required eggs as well
* Use whitelist_externals for the /bin/rm to remove warnings

Note, this change doesn't affect the time of py27/pep8 tasks
executuion!

Change-Id: I2d8ea9f8763fef06935c063f6564a9b239c31caf
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

.gitignore

@@ -44,7 +44,8 @@ vagrant-settings.yaml
 .cache
 
 .tox
-
+ChangeLog
+AUTHORS
 .coverage
 
 

doc-test.conf

@@ -0,0 +1,2 @@
+[DEFAULT]
+repo_name = solar

tox.ini

@@ -8,6 +8,8 @@ usedevelop = True
 install_command = pip install -U {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
 passenv = SOLAR_DB
+
+[testenv:py27]
 deps = -r{toxinidir}/test-requirements.txt
 commands = ostestr
 
@@ -17,12 +19,40 @@ usedevelop = False
 commands =
     flake8 {posargs:solar}
 
-[testenv:docs]
-deps = -r{toxinidir}/requirements.txt
-       sphinx
+[testenv:checkniceness]
+deps = openstack-doc-tools>=0.30
+       doc8
 commands =
-  rm -rf doc/build
+  openstack-doc-test --check-niceness
+  doc8 doc
+
+[testenv:checksyntax]
+deps = openstack-doc-tools>=0.30
+commands =
+  openstack-doc-test --check-syntax
+
+[testenv:docs]
+deps = sphinx
+       {[testenv:checkniceness]deps}
+whitelist_externals = /bin/rm
+commands =
+  /bin/rm -rf doc/build
   python setup.py build_sphinx
+  {[testenv:checkniceness]commands}
+  {[testenv:checksyntax]commands}
+
+[doc8]
+# Settings for doc8:
+# Ignore target directories
+ignore-path = doc/build*
+# File extensions to use
+extensions = .rst,.txt
+# Maximal line length should be 79 but we have some overlong lines.
+# Let's not get far more in.
+max-line-length = 80
+# Disable some doc8 checks:
+# D000: Check RST validity (cannot handle lineos directive)
+ignore = D000
 
 [testenv:venv]
 deps = -r{toxinidir}/requirements.txt