Code owners update

Update CODEOWNERS file to reflect internal structure and reduce load on staff.

.gitlab/CODEOWNERS

-src/ @EIP-devs
-/* @EIP-devs
+# Default rule:
+* @EIP-devs
\ No newline at end of file
+
+# Special casing; these cannot be changed without project owner confirmation
+CODEOWNERS @otto
+LICENSE @otto
+LICENSE.header @otto
+
+# Files that should be looked at by more experienced developers
+/src/ @EIP-devs @Senior-devs
+Contributing.md @EIP-devs @Senior-devs
+README.md @EIP-devs @Senior-devs
+
+# potentially scary changes in here should be covered by the special automagic approval rules
+build.gradle @EIP-devs @Senior-devs
+