Merge pull request #2 from rromanchuk/update-afnetworking

+version of afnetworking
Merge branch 'master' of github.com:usepropeller/afmotion
update to latest afnetworking https://github.com/AFNetworking/AFNetworking/releases
Merge pull request #57 from rromanchuk/version-plus-plus

Bump afnetworking to 2.3.1