Update glutin requirement from 0.21.2 to 0.22.0

Updates the requirements on [glutin](https://github.com/rust-windowing/glutin) to permit the latest version.
- [Release notes](https://github.com/rust-windowing/glutin/releases)
- [Changelog](https://github.com/rust-windowing/glutin/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-windowing/glutin/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

pictor/Cargo.toml

@@ -25,7 +25,7 @@ decorum = "^0.1.1"
 gfx = "0.18.0"
 gfx_device_gl = "0.16.0"
 gfx_window_glutin = "0.31.0"
-glutin = "0.21.2"
+glutin = "0.22.0"
 nalgebra = "^0.19.0"
 num = "^0.2.0"
 rand = "^0.7.0"