Functionality to add custom two-factor auth provider

Refactored code to allow implementation of custom two-factor auth provider.

v0.3.1

Removed authy user registration error

v0.3.0

Send two-factor authentication token via phone call

v0.2.1

Added missing canSendSms implementation

v0.2.0

Feature to select whether two-factor token should be sent via SMS

v0.1.3: Removed SMS token sending error

Removed **Invalid API Key** error when sending two-factor authentication token SMS to user's registered phone.

v0.1.2

Load .env file values.by default.in config

v0.1.1

Removed CSRF check error ....

v0.1

Using this plugin, you can setup two-factor authentication using Laravel.