Add domain-events package to SDK dependencies (#3)

Include complex-heart/domain-events ^1.0.0 in the meta-package.

Author: othercodes

composer.json

@@ -15,6 +15,7 @@
     "ext-json": "*",
     "complex-heart/contracts": "^3.0.0",
     "complex-heart/domain-model": "^5.0.0",
-    "complex-heart/criteria": "^4.0.0"
+    "complex-heart/criteria": "^4.0.0",
+    "complex-heart/domain-events": "^1.0.0"
   }
 }