Various fixes before 3.0

- Fix .ini formatting issues in tox.ini file
- Updated developer docs regarding testing
- Add missing requirements for xosapi
- Fix typo in docs

Change-Id: I3603bbd68c8ecff68d8bbc1a2d4674908c54e5b9
diff --git a/VERSION b/VERSION
index c36c648..8c57128 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.17
+2.2.18