Publish version 0.7.0

Includes:

- Recent removal of sync (breaking change) rust-windowing#191.
- Wayland fixes: rust-windowing#190, rust-windowing#188, rust-windowing#181
- X11 fixes: rust-windowing#174, rust-windowing#178,

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "winit"
-version = "0.6.4"
+version = "0.7.0"
 authors = ["The winit contributors, Pierre Krieger <pierre.krieger1708@gmail.com>"]
 description = "Cross-platform window creation library."
 keywords = ["windowing"]