* Migrate to core::futures
This drops all dependencies on the 'futures' crate, and upgrades to
hyper-0.13 and tokio-0.2. Methods that return futures now use
async/await.
Since hyper has removed hyper_run(), I have in turn removed the
HttpExporter::run() method. The user should just call async_run()
and spawn or await the result however they wish.
* Bump CI minimum rust to 1.39 for async/await
Co-authored-by: Toby Lawrence <tobz@users.noreply.github.com>
Toby Lawrence
Akhil Velagapudi
Daniel Fox Franke
Toby Lawrence