Use jsonschema to validate efficacy indicators

This patch replaces voluptuous with JSON-schema to validate
efficacy indicator since in watcher we want to remove voluptuous
and use JSONSchema as our only JSON validation tool to keep consistency.

Change-Id: Iaa77566f1cdfdac03ce8e7d5a75406274c7d5298
Implements: blueprint replace-voplutuous-with-jsonschema

watcher/applier/actions/base.py

@@ -126,7 +126,7 @@ class BaseAction(loadable.Loadable):
 
         :returns: A schema declaring the input parameters this action should be
                   provided along with their respective constraints
-        :rtype: :py:class:`voluptuous.Schema` instance
+        :rtype: :py:class:`jsonschema.Schema` instance
         """
         raise NotImplementedError()