b2-backblaze

this is a full support async library to access backblaze b2 service backend apis.

features

sample code

```rust

use b2_backblaze::{B2,Config};

[tokio::main]

async fn main() {

//start b2 client
let mut client = B2::new(Config::new(
    "ID".to_string(),
    "KEY".to_string()
));

//set bucket id
client.set_bucket_id("bucket_id".to_string());

//login and start session
match client.login().await{
    Ok(_)=>{
        println!(">>> login successfull");
    },
    Err(_e)=>{
        return println!("!!! login failed : {:?}",_e);
    }
}

//upload file to path
match client.upload(
    "emails/some_email/drink.png".to_string(),
    "d://workstation/expo/rust/letterman/letterman/drink.png".to_string()
).await{
    Ok(_v)=>{
        println!(">>> upload successfull");
    },
    Err(_e)=>{
        return println!("!!! login failed : {:?}",_e);
    }
}

}

```