Fixes an issue where the base url isn't correct for a private app.
Fixes an issue where the thrown exception class 'ApiException' doesn't exist.
Update composer.json
Update composer.json

Reverted changes as they were unnecessary.
Changes to composer.json and the ApiException class

- reverted the composer homepage to the correct entry
- Provided the ability for the api exception to receive an array a param
Added a default for the code.
Decided to use json_encode instead.
Addresses #1.