Changes tox to only run unit tests and moves unit tests to tests/unit.

Currently, the api and scenario tests are skipped when tox is run,
i.e. when tox -e py27 and tox -e py35 are executed. This is not ideal,
because an error could be thrown when trying to import modules into
the api and scenario tests. Instead, these tests should never
be discovered by ostestr. This will resolve issues with the new
framework changes [0].

This change simply creates a new file called test-whitelist.txt
which is used by the parameter --whitelist-file in the
command under [testenv] in tox.ini. It ensures that only
the regexes specified in test-whitelist.txt are executed [1] --
so only the unit tests are executed with tox (as currently
no functional tests are in Patrole).

Also added check-uuid to pep8 in tox.ini.

[0] https://review.openstack.org/#/c/433741/
[1] https://docs.openstack.org/developer/os-testr/ostestr.html

Change-Id: I1c6bca9044a74e8909754f106880636739e5a822
diff --git a/tox.ini b/tox.ini
index 847adad..ba00222 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = py35,py27,pypy,pep8
+envlist = pep8,py35,py27
 skipsdist = True
 
 [testenv]
@@ -9,16 +9,20 @@
 setenv =
    VIRTUAL_ENV={envdir}
    PYTHONWARNINGS=default::DeprecationWarning
-passenv = OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_TEST_TIMEOUT OS_TEST_LOCK_PATH OS_TEST_PATH TEMPEST_CONFIG TEMPEST_CONFIG_DIR http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
-whitelist_externals = *
+passenv = OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_TEST_TIMEOUT OS_TEST_LOCK_PATH OS_TEST_PATH http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+whitelist_externals = find
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = 
     find . -type f -name "*.pyc" -delete
-    ostestr {posargs}
+    ostestr {posargs} --whitelist-file test-whitelist.txt
 
 [testenv:pep8]
 commands = flake8 {posargs}
+		   check-uuid
+
+[testenv:uuidgen]
+commands = check-uuid --fix
 
 [testenv:venv]
 commands = {posargs}