Update CODEOWNERS (#84)

Point to the GitHub group instead of directly
to people.

Signed-off-by: Ry Jones <ry@linux.com>

CODEOWNERS

@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # Fabric SDK Node maintainers
-*	@andrew-coleman @christo4ferris @JonathanLevi @harrisob @mastersingh24 @smithbk @zhaochy1990 @bestbeforetoday
+*	@hyperledger/fabric-sdk-node-maintainers