Remove AFNetwork from Readme
Add section numbers in Readme for additional features
Add section about delegate callbacks to Readme
Test more Activity Handler
Add migration instructions to doc/migration.md
Update image links in documentation
Tests Request Handler buffered
Merge branch 'source_access' of https://github.com/adeven/adjust_ios_sdk into unit
Remove test files
Add test files

This reverts commit 2a5262c292a110d24009ab9981e430ba4b4a98a0.