EvangelistFetcher.php

[unicodeveloper]

Inconsistent spacing around your comments. You gave a space immediately after the comments for some functions while the others didn't have that. Please fix!

[unicodeveloper]

public function getData($username)
    {
        static::loadDotenv();
        try {
            if (empty($username)) {
                throw new NullUserException();
            }
            $client   = new Client();
            $response = $client->get('https://api.github.com/users/'.$username. '?client_id=' .getenv('Client_ID') . '&client_secret=' .getenv('Client_SECRET'));
            return $response->json()['public_repos'];
        } catch (ClientException $e) {
            return "Unregistered User!";
        } catch (NullUserException $e) {
            return $e->message();
        }
    }

Instantiating the Client class inside this function is not cool, it's gonna be hard to test for that class there. I recommend that you use the concept of dependency injection to load the instance of Client class like so:

public function getData($username, Client $client)

then when the getData is called, you'll just pass an instance of Client like so: getData('andela-prosper', new Client)

[unicodeveloper]

The if block where you were checking if the $username was empty shouldn't be inside the try and catch block

[sirolad]

It has been re-factored to use DI.