No more Makefile and a little cleanup.

.gitignore

@@ -46,8 +46,4 @@ dist/
 *.lock
 *.env
 .bundle/
-debian
-ubuntu
-centos
-fedora
-alpine
+*.touch

.travis.yml

@@ -7,7 +7,7 @@ services:
   - docker
 
 script:
-  - make test clean
+  - bats test.bats
 
 notifications:
   email: false

Makefile

-.PHONY: test clean
-
-test:
-	bats test.bats
-
-clean:
-	docker image ls --format '{{.ID}}' runas-* | xargs -r docker image rm
-	rm -f debian fedora ubuntu alpine

test.bats

@@ -5,9 +5,14 @@ _test () {
     tag="${2:-latest}"
     userland="${3:-gnu}"
     docker build -t "runas-$name" --build-arg "image=$name:$tag" --build-arg "userland=$userland" ./
-    docker run --rm -v "$BATS_TEST_DIRNAME:/volume" "runas-$name" touch "$name"
-    test "$(id -u)" = "$(stat -c '%u' $name)"
-    test "$(id -g)" = "$(stat -c '%g' $name)"
+    docker run --rm -v "$BATS_TEST_DIRNAME:/volume" "runas-$name" touch "$name.touch"
+    test "$(id -u)" = "$(stat -c '%u' $name.touch)"
+    test "$(id -g)" = "$(stat -c '%g' $name.touch)"
+}
+
+teardown () {
+    docker image ls --format '{{.ID}}' runas-* | xargs -r docker image rm
+    rm -f *.touch
 }
 
 @test "ubuntu" { _test; }