Add Push Api

[shirakun]

Hi
Added the ability to submit licenses via api to it.

[totoroterror]

Hello! Thanks for your contribution, but I don't think that this is needed now. It's a great feature, but most of people just won't use it. Also, your API isn't sending such variables: referral_count, private_key, peer_endpoint, peer_public_key, interface_addresses, they are quite important.

[totoroterror]

Implemented in 13978c3