Added table of contents to README

Merge pull request #69 from NinoSkopac/v2.4.5

V2.4.5: Added table of contents to README

IDE Hints and timeout setting

Merge pull request #67 from NinoSkopac/2.4.3

IDE hints for endpoints in PromisePay.php

Fixes #63

Merge pull request #64 from NinoSkopac/2.4.2

2.4.2: Fixes #63

Fixes namespace and setDisbursementAccount() in readme

Merge pull request #59 from NinoSkopac/v2.4.1

V2.4.1: Fix namespace and setDisbursementAccount() in readme

Feature Configurations, Payment Restrictions and Callbacks

New Features

• Feature Configurations,
• Payment Restrictions
• Callbacks

Changes

• PHP5.3 removed in Travis buildpack (this doesn't change code compatibility with that version of PHP)

Fixes

• README.md

Notes

• Feature Configurations and Payment Restrictions were part of #38 but never merged.
• Issue tracker for Callbacks: #45

2.3.1

Merge pull request #35 from NinoSkopac/master

v.2.3 and v2.3.1