Disable gomod when running fossa

Go is unable to convert our Gopkg.toml into a go mod.

Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>

Author: rumpl

Makefile

@@ -109,7 +109,7 @@ coverage: coverage-test-unit coverage-test-e2e ## run tests with coverage
 
 fossa-analyze:
 	docker run -i --rm -e FOSSA_API_KEY \
-		-e GO111MODULE=on \
+		-e GO111MODULE=off \
 		-v $(CURDIR)/$*:/go/src/github.com/docker/app \
 		-w /go/src/github.com/docker/app \
 		$(BUILD_ANALYZER) analyze $(FOSSA_OPTS) --branch $(BRANCH_NAME)