stdlib: Add GCS support

The interface and behavior is identical to S3.

Signed-off-by: Scott Lewis-Kelly <slewiskelly@slewiskel.ly>

stdlib/gcp/gcs/tests/gcs.cue

@@ -0,0 +1,33 @@
+package gcs
+
+import (
+	"alpha.dagger.io/dagger"
+	"alpha.dagger.io/gcp"
+)
+
+TestConfig: gcpConfig: gcp.#Config
+
+bucket: "dagger-ci"
+
+TestDirectory: dagger.#Artifact
+
+TestGCSObject: {
+	deploy: #Object & {
+		always: true
+		config: TestConfig.gcpConfig
+		source: TestDirectory
+		target: "gs://\(bucket)/"
+	}
+
+	verifyFile: #VerifyGCS & {
+		config: TestConfig.gcpConfig
+		target: deploy.target
+		file:   "dirFile.txt"
+	}
+
+	verifyDir: #VerifyGCS & {
+		config: TestConfig.gcpConfig
+		target: deploy.target
+		file:   "foo.txt"
+	}
+}