tox: Test ryu-manager without additional requirements

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

tox.ini

@@ -2,14 +2,18 @@
 envlist = py27,py34,py35,pypy26,pep8
 
 [testenv]
-deps = -U
-       -r{toxinidir}/tools/pip-requires
-       -r{toxinidir}/tools/optional-requires
-       -r{toxinidir}/tools/test-requires
-       --no-cache-dir
+deps =
+  -U
+  -r{toxinidir}/tools/pip-requires
+  --no-cache-dir
 usedevelop = True
 passenv= NOSE_VERBOSE
+# Note: To check whether tools/pip-requires satisfies the requirements
+# for running Ryu, the following runs ryu-manager berfore installing
+# the addtional requirements.
 commands =
+  ryu-manager ryu/tests/unit/cmd/dummy_openflow_app.py
+  pip install -r{toxinidir}/tools/optional-requires -r{toxinidir}/tools/test-requires
   coverage run --source=ryu ryu/tests/run_tests.py '{posargs}'
 
 [testenv:scenario]
@@ -28,6 +32,10 @@ commands =
   {[testenv:scenario]commands}
 
 [testenv:pep8]
+deps =
+  -U
+  --no-cache-dir
+  pep8
 commands =
   pep8