Allow parallel v0.1 and v0.2

Author: kelunik

composer.json

@@ -19,7 +19,7 @@
     },
     "require": {
         "php": ">=7",
-        "amphp/parallel": "^0.1",
+        "amphp/parallel": "^0.1.8 || ^0.2",
         "amphp/amp": "^2",
         "opis/closure": "^3.0.7"
     },