Fix a typo in comments.

1Weather/Model/ModelObjects/Location.swift

@@ -81,7 +81,7 @@ extension Location: UpdatableModelObject {
     public func mergedWith(incrementalChanges: Location) -> Location {
         var result = self
         result.lastTimeUpdated = incrementalChanges.lastTimeUpdated
-        // The preferense is given to self values rather than incrementalChanges in this class
+        // The preference is given to self values rather than incrementalChanges in this class
         result.coordinates = result.coordinates ?? incrementalChanges.coordinates
         result.imageName = result.imageName ?? incrementalChanges.imageName
         result.countryCode = result.countryCode ?? incrementalChanges.countryCode