Cleaned up *-requirements.txt

* Added six, oslo-config, tempest, testtools, requests to
  requirements.txt as these modules are used in tempest plugin.

* Removed unused dependencies from test-requirements.txt

Change-Id: I86ee5704be736e5be5fe19951d9121eb213b4794
diff --git a/requirements.txt b/requirements.txt
index 485ba11..99f48af 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,8 @@
 
 # xml parsing
 lxml!=3.7.0,>=2.3 # BSD
+tempest>=12.1.0 # Apache-2.0
+oslo.config>=3.22.0 # Apache-2.0
+testtools>=1.4.0  # MIT
+six>=1.9.0
+requests>=2.14.2 # Apache-2.0