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/containers/chameleon/Dockerfile.chameleon b/containers/chameleon/Dockerfile.chameleon
index b18ec5c..2b218e4 100644
--- a/containers/chameleon/Dockerfile.chameleon
+++ b/containers/chameleon/Dockerfile.chameleon
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/chameleon
-FROM xosproject/xos-base:2.2.17
+FROM xosproject/xos-base:2.2.18
 
 # xos-base already has protoc and dependencies installed
 
diff --git a/containers/xos/Dockerfile.client b/containers/xos/Dockerfile.client
index e731bcf..bc01347 100644
--- a/containers/xos/Dockerfile.client
+++ b/containers/xos/Dockerfile.client
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-client
-FROM xosproject/xos-libraries:2.2.17
+FROM xosproject/xos-libraries:2.2.18
 
 # Install XOS client
 COPY lib/xos-api /tmp/xos-api
diff --git a/containers/xos/Dockerfile.libraries b/containers/xos/Dockerfile.libraries
index f87792f..590a2e9 100644
--- a/containers/xos/Dockerfile.libraries
+++ b/containers/xos/Dockerfile.libraries
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-libraries
-FROM xosproject/xos-base:2.2.17
+FROM xosproject/xos-base:2.2.18
 
 # Add libraries
 COPY lib /opt/xos/lib
diff --git a/containers/xos/Dockerfile.synchronizer-base b/containers/xos/Dockerfile.synchronizer-base
index 75a9b9e..175b378 100644
--- a/containers/xos/Dockerfile.synchronizer-base
+++ b/containers/xos/Dockerfile.synchronizer-base
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-synchronizer-base
-FROM xosproject/xos-client:2.2.17
+FROM xosproject/xos-client:2.2.18
 
 COPY xos/synchronizers/new_base /opt/xos/synchronizers/new_base
 COPY xos/xos/logger.py /opt/xos/xos/logger.py
diff --git a/containers/xos/Dockerfile.xos-core b/containers/xos/Dockerfile.xos-core
index 7a71462..8ed98f9 100644
--- a/containers/xos/Dockerfile.xos-core
+++ b/containers/xos/Dockerfile.xos-core
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # xosproject/xos-core
-FROM xosproject/xos-libraries:2.2.17
+FROM xosproject/xos-libraries:2.2.18
 
 # Install XOS
 ADD xos /opt/xos