Improve #docker.Push definition :

- Push to private registry
- Output ref and digest
- Update doc
- Add tests to universe.bats

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

stdlib/.dagger/env/docker-push-invalid-creds/.gitignore

@@ -0,0 +1,2 @@
+# dagger state
+state/**

stdlib/.dagger/env/docker-push-invalid-creds/plan/push.cue

@@ -0,0 +1,34 @@
+package docker
+
+import (
+	"dagger.io/docker"
+	"dagger.io/random"
+)
+
+TestRegistry: {
+	username: string @dagger(input)
+	secret:   string @dagger(input)
+}
+
+TestPush: {
+	tag: random.#String & {seed: "docker push and pull should fail"}
+
+	name: "daggerio/ci-test:\(tag.out)"
+
+	image: docker.#ImageFromDockerfile & {
+		dockerfile: """
+				FROM alpine
+				RUN echo "test" > /test.txt
+			"""
+		context: ""
+	}
+
+	push: docker.#Push & {
+		"name": name
+		source: image
+		registry: {
+			username: TestRegistry.username
+			secret:   TestRegistry.secret
+		}
+	}
+}

stdlib/.dagger/env/docker-push-invalid-creds/values.yaml

@@ -0,0 +1,26 @@
+name: docker-push-invalid-creds
+inputs:
+    TestRegistry.secret:
+        text: ENC[AES256_GCM,data:QOkT,iv:MUV92Llmt8pskd1AUjnvpQ+B3Ws1wLKIuzy7SVhHRME=,tag:StNvPnmz89GcLb1Cro3O9g==,type:str]
+    TestRegistry.username:
+        text: john
+sops:
+    kms: []
+    gcp_kms: []
+    azure_kv: []
+    hc_vault: []
+    age:
+        - recipient: age1gxwmtwahzwdmrskhf90ppwlnze30lgpm056kuesrxzeuyclrwvpsupwtpk
+          enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB3MC9DZGU1Tm5Ta2ttNUph
+            ZGxZaGxLMklRRWVaVmtzdEdqbnlkYmIvK2hNClVKd2RCak1GYXlvZWQxaHlzQUNw
+            Y2czeEdXZnQxT2dVQ01GY0NTcGNkMnMKLS0tIGwwa0xXVEZQUVUzdUpOQUJFTUxy
+            ZzZNNk1xb0F4cWVQRjh4aUJSUzExd2cKl0Ka0Qcc2KNOQjl3Bhnb1sGuJCZ6iDs4
+            Hz2EldaxWJHZxuS18uNC38NxufG02ULJqJb2QC4cOzPrTeeKVE6Qlg==
+            -----END AGE ENCRYPTED FILE-----
+    lastmodified: "2021-06-12T15:03:49Z"
+    mac: ENC[AES256_GCM,data:o2fTjTnDgSX4f2jSjs1LSKJ7eTrTmFV44gyZdYCdYnb6eyXpFuT4Bru8ERuJlTvUSc3wx4js14BlxS3T0tX0aBV39ScBlzQOC4Ulyvh4KOKEH9uUl7YmGrFlNH4yQ7DYoezxCqwxlLZGavDaSXUszvKWlcdMsTm3L/4LkfHQzWk=,iv:E1gyYQ0+02bIQguvN0w+wp8RS6uyT17tXp18e5riXmg=,tag:Azjz4ZivYmjC/7eMc6SfSQ==,type:str]
+    pgp: []
+    encrypted_suffix: secret
+    version: 3.7.1