Update to Rust edition 2021 (#39)

* Update to Rust edition 2021

* Fix crate name in README

.circleci/config.yml

@@ -1,7 +1,7 @@
 # Check that everything (tests, benches, etc) builds in std environments
 precheck_steps: &precheck_steps
   docker:
-    - image: jamwaffles/circleci-embedded-graphics:1.40.0-3
+    - image: jamwaffles/circleci-embedded-graphics:1.57.0-0
       auth:
         username: jamwaffles
         password: $DOCKERHUB_PASSWORD

CHANGELOG.md

@@ -6,7 +6,10 @@
 
 ## [Unreleased] - ReleaseDate
 
+### Changed
+
 - [#34](https://github.com/embedded-graphics/simulator/pull/34) Bump minimum embedded-graphics version from 0.7.0 to 0.7.1.
+- **(breaking)** [#39](https://github.com/embedded-graphics/simulator/pull/39) Bump Minimum Supported Rust Version (MSRV) to 1.57.
 
 ## [0.3.0] - 2021-06-05
 
@@ -22,7 +25,7 @@
 
 ### Changed
 
-- **(breaking**) [#29](https://github.com/embedded-graphics/simulator/pull/29) Color types used in `Window::update`and `Window::show_static` must now implement `From<Rgb888>`.
+- **(breaking)** [#29](https://github.com/embedded-graphics/simulator/pull/29) Color types used in `Window::update`and `Window::show_static` must now implement `From<Rgb888>`.
 
 ### Fixed
 

Cargo.toml

@@ -9,7 +9,7 @@ categories = ["embedded", "no-std"]
 keywords = ["embedded-graphics", "simulator", "graphics", "embedded"]
 readme = "./README.md"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 exclude = [
     "/.circleci/",
     "/.github/",
@@ -20,12 +20,12 @@ exclude = [
 circle-ci = { repository = "embedded-graphics/simulator", branch = "master" }
 
 [dependencies]
-image = "0.23.0"
+image = "0.23.14"
 base64 = "0.13.0"
 embedded-graphics = "0.7.1"
 
 [dependencies.sdl2]
-version = "0.32.2"
+version = "0.35.1"
 optional = true
 
 [features]

README.md

@@ -141,6 +141,11 @@ See the [Choosing
 Features](https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#choosing-features)
 Cargo manifest documentation for more details.
 
+## Minimum supported Rust version
+
+The minimum supported Rust version for embedded-graphics-simulator is `1.57` or greater.
+Ensure you have the correct version of Rust installed, preferably through <https://rustup.rs>.
+
 ## License
 
 Licensed under either of

README.tpl

@@ -9,6 +9,11 @@
 
 {{readme}}
 
+## Minimum supported Rust version
+
+The minimum supported Rust version for embedded-graphics-simulator is `1.57` or greater.
+Ensure you have the correct version of Rust installed, preferably through <https://rustup.rs>.
+
 ## License
 
 Licensed under either of