Add Rhys and Rahul as codeowners (#28)

**Description** <Describe what changed.>
This PR adds Rhys and Rahul as CODEOWNERS so they can make and approve
updates moving forward.

**Testing** <Describe how you tested the change.>
N/A

**Documentation** <Describe any documentation that was added.>
The request came from Rhys.

.github/CODEOWNERS

@@ -1,2 +1,4 @@
 * @strata-io/octo
+* @rhysecampbell
+* @rvyas-strata
 * @wfernandes