Don't quote {posargs} in tox.ini

Quotes around {posargs} cause the entire string to be combined into one
arg that gets passed to stestr. This prevents passing multiple args
(e.g. '--concurrency=16 some-regex')

Change-Id: I7c45e4525f255deec7c79ae567cf4b1dda111a4a

tox.ini

@@ -13,7 +13,7 @@ whitelist_externals = find
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
-  stestr run '{posargs}'
+  stestr run {posargs}
   stestr slowest
 
 [testenv:api-ref]
@@ -78,7 +78,7 @@ commands = flake8
            find . -type f -name "*.pyc" -delete
            python -m unittest specs-tests.test_titles
            sh ./tools/misc-sanity-checks.sh
-           {toxinidir}/tools/coding-checks.sh --pylint '{posargs}'
+           {toxinidir}/tools/coding-checks.sh --pylint {posargs}
 whitelist_externals =
   sh
   find
@@ -172,7 +172,7 @@ passenv = TEMPEST_CONFIG_DIR
 setenv =
  OS_TEST_PATH={toxinidir}/octavia/tests/tempest/v1/api
 commands =
-  stestr run --concurrency 1 '{posargs}'
+  stestr run --concurrency 1 {posargs}
   stestr slowest
 
 # If you are running the tests locally you should set the env variable
@@ -183,7 +183,7 @@ passenv = TEMPEST_CONFIG_DIR
 setenv =
  OS_TEST_PATH={toxinidir}/octavia/tests/tempest/v1/scenario
 commands =
-  stestr run --concurrency 1 '{posargs}'
+  stestr run --concurrency 1 {posargs}
   stestr slowest
 
 [testenv:lower-constraints]