Rename import anguslees/kubecfg -> bitnami/kubecfg

Repo was (at least initially) published under bitnami/ - make imports
consistent with that path.

main.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/anguslees/kubecfg/cmd"
+	"github.com/bitnami/kubecfg/cmd"
 )
 
 // Version is overridden using `-X main.version` during release builds

vendor/vendor.json

@@ -33,5 +33,5 @@
 			"revisionTime": "2017-04-18T07:42:43Z"
 		}
 	],
-	"rootPath": "github.com/anguslees/kubecfg"
+	"rootPath": "github.com/bitnami/kubecfg"
 }