Update Rust edition to 2021.

Author: xStrom

docs/book_examples/Cargo.toml

@@ -1,8 +1,11 @@
 [package]
 name = "book_examples"
 version = "0.1.0"
+license = "Apache-2.0"
+repository = "https://github.com/linebender/druid"
 authors = ["Colin Rofls <[email protected]>"]
-edition = "2018"
+edition = "2021"
+publish = false
 
 [dependencies]
 druid = { path = "../../druid", features = [ "im" ] }

druid-shell/Cargo.toml

@@ -7,7 +7,7 @@ description = "Platform abstracting application shell used for druid toolkit."
 repository = "https://github.com/linebender/druid"
 readme = "README.md"
 categories = ["os::macos-apis", "os::windows-apis", "gui"]
-edition = "2018"
+edition = "2021"
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "docsrs"]

druid/Cargo.toml

@@ -8,7 +8,7 @@ repository = "https://github.com/linebender/druid"
 categories = ["gui"]
 readme = "README.md"
 keywords = ["gui", "ui", "toolkit"]
-edition = "2018"
+edition = "2021"
 
 [package.metadata.docs.rs]
 # The "svg" and "image" features have doc clashes that cause undefined output in docs.

druid/examples/hello_web/Cargo.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 license = "Apache-2.0"
 description = "Minimal web example"
 repository = "https://github.com/linebender/druid"
-edition = "2018"
+edition = "2021"
 publish = false
 
 [lib]

druid/examples/value_formatting/Cargo.toml

@@ -1,8 +1,11 @@
 [package]
 name = "value-formatting"
 version = "0.1.0"
+license = "Apache-2.0"
+repository = "https://github.com/linebender/druid"
 authors = ["Colin Rofls <[email protected]>"]
-edition = "2018"
+edition = "2021"
+publish = false
 
 [dependencies]
 druid = { path = "../../" }

druid/examples/web/Cargo.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 license = "Apache-2.0"
 description = "Scaffolding for druid web examples"
 repository = "https://github.com/linebender/druid"
-edition = "2018"
+edition = "2021"
 publish = false
 
 [lib]