Since #642 refactoring increased test coverage and mutation test coverage, we raise the minMsi again

We now cover more edges in `PublicScopeSimulator`, and that should be reflected in our mutation score
requirements.

Author: Ocramius

infection.json.dist

@@ -10,6 +10,6 @@
             "branch": "master"
         }
     },
-    "minMsi": 84,
+    "minMsi": 84.3,
     "minCoveredMsi": 86
 }