Update to latest futures

Author: kpp

.travis.yml

@@ -1,7 +1,7 @@
 language: rust
 sudo: false
 rust:
-  - nightly-2019-05-10
+  - nightly-2019-06-26
 
 os:
  - linux

Cargo.toml

@@ -14,5 +14,5 @@ edition = "2018"
 pin-utils = "=0.1.0-alpha.4"
 
 [dependencies.futures]
-version = "=0.3.0-alpha.15"
+version = "=0.3.0-alpha.16"
 package = "futures-preview"

README.md

@@ -9,7 +9,7 @@ like `FutureExt::map`, `TryFutureExt::and_then`...
 
 # Requirements
 
-Rust nightly-2019-04-26 for async_await, await_macro...
+Rust nightly-2019-06-26 for async_await, await_macro...
 
 # State