Correct Bucket#[]= documentation
Correct Bucket#[]= documentation

thanks to @vmx

Change-Id: I3fcf7774719787e809922d42aecdbef11ce1e3d5
Reviewed-on: http://review.couchbase.org/25333
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>
Tested-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

dewolfe/couchbase-ruby-client,dewolfe/couchbase-ruby-client