Update bitflags requirement to 1.0 in /iui

Updates the requirements on [bitflags](https://github.com/rust-lang-nursery/bitflags) to permit the latest version.
- [Release notes](https://github.com/rust-lang-nursery/bitflags/releases)
- [Changelog](https://github.com/rust-lang-nursery/bitflags/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang-nursery/bitflags/commits/1.0.1)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot-support

iui/Cargo.toml

@@ -43,7 +43,7 @@ is-it-maintained-open-issues = { repository = "LeoTindall/libui-rs" }
 maintenance = { status = "actively-developed" }
 
 [dependencies]
-bitflags = "0.7"
+bitflags = "1.0"
 libc = "0.2"
 failure = "0.1.1"
 ui-sys = "0.1.1"