Merge pull request #1301 from TomChv/europa/write-file-default-permission

Add default value to permissions to `#WriteFile`

stdlib/europa/dagger/engine/fs.cue

@@ -43,7 +43,7 @@ package engine
 	// Contents to write
 	contents: string
 	// Permissions of the file
-	permissions: int
+	permissions: *0o600 | int
 	// Output filesystem tree
 	output: #FS
 }

tests/plan/outputs/outputs.cue

@@ -7,10 +7,10 @@ engine.#Plan & {
 		scratch: engine.#Scratch
 
 		data: engine.#WriteFile & {
-			input:    scratch.output
-			path:     "/test"
-			mode:     0o600
-			contents: "foobar"
+			input:       scratch.output
+			path:        "/test"
+			permissions: 0o600
+			contents:    "foobar"
 		}
 	}