Bump version to 0.3.0

Author: simonbrunel

qpm.json

@@ -10,7 +10,7 @@
         "url": "https://github.com/simonbrunel/qtpromise.git"
     },
     "version": {
-        "label": "0.2.0"
+        "label": "0.3.0"
     },
     "license": "MIT",
     "pri_filename": "qtpromise.pri",