Changes for async API (non-blocking reqwest)

[leodutra]

Implements async send() + async fetch_resource() and implements changes for the new usage (+examples).

This change is required to enable the API to be used in async scopes using async runtime, like actix-web 2.0. Otherwise, a "trying to block into async thread" [sic] error occurs.

The examples use futures crate to keep the code as close to the last version as possible.

I was able to test into my own private chatbot, it's working as expected.

This should probably become a 4.x version.

[biomunky]

Hi, can you bump the version. Let’s get this in.

[biomunky]

When I run the examples I'm getting a panic

Running target/debug/examples/get_sources thread 'main' panicked at 'not currently running on the Tokio runtime.', /Users/dan/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.16/src/runtime/handle.rs:69:9 note: run with RUST_BACKTRACE=1 environment variable to display a backtrace

[biomunky]

The panic can be solved by doing the following.

Add tokio to Cargo.toml

tokio = { version = "0.2", features = ["full"] }

Modify the examples to use the tokio main macro. Using full as this is recommended in the docs when starting out.

#[tokio::main]
async fn main() { ... }

While the async stuff is cool, I'm not sure I'm comfortable with throwing the synchronous client away. Perhaps a refactor is in order so that we can support async and sync clients?

[leodutra]

Sounds good. It's late my time, and sorry for the delay, but I'll do it ASAP.

[biomunky]

Sounds good. It's late my time, and sorry for the delay, but I'll do it ASAP.

No rush, this is supposed to be fun rather than work.

[leodutra]

Hey @biomunky. Sorry, I totally missed this PR. I kept the sync API, added some _sync suffix for the 2 sync/ async methods we have, fixed the examples and repeated them for sync versions.

[biomunky]

cool, likewise missed :) will look tomorrow.

[biomunky]

I'm going to merge and then make some more changes before releasing a new version.