Add revoke_collection_authority

[0xIchigo]

In our Node.js SDK, we have the revokeCollectionAuthority method, which revokes collection authority from an address. This is handy when used with our Mint API. We should add this functionality to the Rust SDK

[grandima]

I tried to dig into this issue and I found that Node.js SDK uses Metaplex to make NFT requests under the hood. Should the solution to this issue rely on some Rust alternative library to Metaplex or write all the necessary code (structs, requests) in Rust SDK library?

[0xIchigo]

@grandima, I haven't dug into it yet so I'm not 100% sure. It hasn't been a huge priority, so it's your call — whatever works best!

[grandima]

@0xIchigo hey! The PR #77 is ready. Feel free to review.

It also contains changes to #16 because in order to test #17 #16 had to be implemented.

[0xIchigo]

Can we considered closed now that #77 has been merged