Add test_pam_goatherd make target

Makefile

@@ -10,7 +10,10 @@ goatherd: goatherd.go
 test_pg: goatherd.go goatherd_test.go test_pg.sh
 	sh test_pg.sh
 
-test: test_pg
+test_pam_goatherd: goatherd pam_goatherd.so test_pam_goatherd.sh
+	sh test_pam_goatherd.sh
+
+test: test_pg test_pam_goatherd
 
 pam_goatherd.so: pam_goatherd.o
 	$(LINK.c) -lpam -lgnutls -Wl,-soname,$@ -shared $< -o $@
@@ -26,4 +29,4 @@ install_daemon: goatherd
 
 install: install_pam install_daemon
 
-.PHONY: all clean test test_pg install install_daemon install_pam
+.PHONY: all clean test test_pg test_pam_goatherd install install_daemon install_pam