Working with v2 whether api with optional min/max temp for next days.

@jasperblues I create min and max temp optional values for the next days so now application works with test keys with v2 of the weather api.

in the Configuration.plist there was api key that works with min and max temp. I removed it and I put $$YOUR_API_KEY_HERE$$. I tested with both cases - was ok - application don't crash.