meta/bandwidth: package main so we can build a binary

plugins/meta/bandwidth/bandwidth_suite_test.go

@@ -1,5 +1,3 @@
-package bandwidth
-
 // Copyright 2018 CNI authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -13,6 +11,7 @@ package bandwidth
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+package main
 
 import (
 	"bytes"