Remove install unnecessary packages

The docs requirements migrated to doc/requirements.txt
we need not install things from requirements.txt.

Change-Id: I90212bdb5f2663851b02c58538c5b54e5c9bf4a9
diff --git a/tox.ini b/tox.ini
index 031a400..2ea8129 100644
--- a/tox.ini
+++ b/tox.ini
@@ -279,7 +279,6 @@
 [testenv:docs]
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-  -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-apidoc -f -o doc/source/tests/compute tempest/api/compute
@@ -365,7 +364,6 @@
 [testenv:releasenotes]
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-  -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
 commands =
   rm -rf releasenotes/build