The "peer channel fetch" and "peer chaincode install" commands
currently log their success output message at the debug level.
This can make certain integration/e2e tests fail unexpectedly
if the log level is set to any other level.

It seems natural that the logged success message should be at
the info level.

Change-Id: I8ad961a5b55b7a353f329218d9090457ed1bf0be
Signed-off-by: Will Lahti <wtlahti@us.ibm.com>