increment metadata version (#412)

What this PR does / why we need it:
Increment metadata version.

Which issue(s) this PR fixes (optional, in fixes #(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Author: vladcristi

metadata.yaml

@@ -59,3 +59,6 @@ releaseSeries:
   - major: 0
     minor: 18
     contract: v1beta1
+  - major: 0
+    minor: 19
+    contract: v1beta1