Update jsonrpc dependencies and rewrite dapps to futures. (#6522)

* Bump version.

* Fix RPC crate.

* Fix BoxFuture in crates.

* Compiles and passes tests!

* Get rid of .boxed()

* Fixing issues with the UI.

* Remove minihttp. Support threads.

* Reimplement files serving to do it in chunks.

* Increase chunk size.

* Remove some unecessary copying.

* Fix tests.

* Fix stratum warning and ipfs todo.

* Switch to proper branch of jsonrpc.

* Update Cargo.lock.

* Update docs.

* Include dapps-glue in workspace.

* fixed merge artifacts

* Fix test compilation.

ethcore/src/engines/validator_set/multi.rs

@@ -164,8 +164,6 @@ mod tests {
 
 	#[test]
 	fn uses_current_set() {
-		let _ = ::env_logger::init();
-
 		let tap = Arc::new(AccountProvider::transient_provider());
 		let s0: Secret = keccak("0").into();
 		let v0 = tap.insert_account(s0.clone(), "").unwrap();