test.bash: limit running go test to integration_test.go only

Change-Id: Ib2e96183b99deddbbd3132cd2ca6fa34a25994c6
Reviewed-on: https://go-review.googlesource.com/c/164645
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

regenerate.bash

@@ -4,5 +4,5 @@
 # license that can be found in the LICENSE file.
 
 cd "$(git rev-parse --show-toplevel)"
-go test -v -timeout 60m -tags integration "$@" -regenerate
+go test -v -timeout 60m integration_test.go "$@" -regenerate
 exit $?

test.bash

@@ -4,5 +4,5 @@
 # license that can be found in the LICENSE file.
 
 cd "$(git rev-parse --show-toplevel)"
-go test -v -timeout 60m -tags integration "$@"
+go test -v -timeout 60m integration_test.go "$@"
 exit $?