fix(Makefile): speed up all makefile builds

before, we ran ‘glide nv’ before *all* commands, but it was only used
in the ‘test’ target. this commit only runs it as part of that target

Makefile

@@ -27,8 +27,6 @@ RC := manifests/deis-${SHORT_NAME}-rc.yaml
 SVC := manifests/deis-${SHORT_NAME}-service.yaml
 IMAGE := ${DEIS_REGISTRY}${IMAGE_PREFIX}/${SHORT_NAME}:${VERSION}
 
-TEST_PACKAGES := $(shell ${DEV_ENV_CMD} glide nv)
-
 all:
 	@echo "Use a Makefile to control top-level building of the project."
 
@@ -46,7 +44,7 @@ build:
 	@$(call check-static-binary,$(BINARY_DEST_DIR)/boot)
 
 test:
-	${DEV_ENV_CMD} go test ${TEST_PACKAGES}
+	${DEV_ENV_CMD} sh -c 'go test $$(glide nv)'
 
 docker-build:
 	docker build --rm -t ${IMAGE} rootfs