Fix package names for executables.
Go 1.6 fixed a bug where compiling with the -pack flag allowed non-main
packages to link.
https://github.com/golang/go/issues/13468
This change uses package main for choosestage and gotestmain.
diff --git a/choosestage/choosestage.go b/choosestage/choosestage.go
index c3d0273..3cacf02 100644
--- a/choosestage/choosestage.go
+++ b/choosestage/choosestage.go
@@ -29,7 +29,7 @@
// The timestamp of the first file is not updated so that it can be regenerated
// with any local changes.
-package choosestage
+package main
import (
"bytes"
diff --git a/gotestmain/gotestmain.go b/gotestmain/gotestmain.go
index 0c2ca3d..20af754 100644
--- a/gotestmain/gotestmain.go
+++ b/gotestmain/gotestmain.go
@@ -12,7 +12,7 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-package gotestmain
+package main
import (
"bytes"
