Add tests on docker.#Build definition

- Simple build test
- Multi step to build a go binary

Signed-off-by: Vasek - Tom C <tom.chauveau@epitech.eu>

pkg/universe.dagger.io/docker/test/docker.bats

@@ -5,6 +5,9 @@ setup() {
 }
 
 @test "docker.#Build" {
+    dagger up ./build-simple.cue
+    dagger up ./build-multi-steps.cue
+
     dagger up ./nested-build-test.cue
 
     # FIXME: this is currently broken