Updating code style, PHP Unit and adding Psalm

A patch release of the Weather Underground API client with some code style updates and the most current PHP Unit and Psalm versions. No new methods or functions.

Updated API + Tests

The second release of the Weather Underground API client gives you some new methods to get weather data and also contains unit tests (thanks to @stebogit !!).

New methods are:

• getByUSCity($state, $city)
• getForecast($location)
• getExtendedForecast($location)
• getHistoric($date, $location)

First working release

The first release of the Weather Underground API client gives you some simple query methods to get weather data. The most simple setup looks like this:

// By default the current conditions will be requested in english language.
$weather = (new \lfischer\wunderground\API('<API-key here>'))->getByLocation('Germany', 'Dusseldorf');

There are a few default settings, you might want to check out (see the README)