Update crate versions in 05-led-roulette

Cargo.toml
  * edition             2018 -> 2021
  * microbit-v2         0.12.0 -> 0.14.0
  * microbit            0.12.0 -> 0.14.0
  * cortex-m            0.7.3 -> 0.7.7, added feature `critical-section-single-core`
  * cortex-m-rt         0.7.0 -> 0.7.3
  * rtt-target          0.3.1 -> 0.5.0, removed feature `cortex-m`
  * panic-rtt-target    0.1.2 -> 0.1.3, removed feature `cortex-m`

Author: nikgul

microbit/src/05-led-roulette/Cargo.toml

@@ -2,28 +2,28 @@
 name = "led-roulette"
 version = "0.1.0"
 authors = ["Henrik Böving <hargonix@gmail.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies.microbit-v2]
-version = "0.12.0"
+version = "0.14.0"
 optional = true
 
 [dependencies.microbit]
-version = "0.12.0"
+version = "0.14.0"
 optional = true
 
 [dependencies]
-cortex-m = "0.7.3"
-cortex-m-rt = "0.7.0"
+cortex-m = { version = "0.7.7", features = ["critical-section-single-core"] }
+cortex-m-rt = "0.7.3"
 panic-halt = "0.2.0"
-#rtt-target = { version = "0.3.1", features = ["cortex-m"] }
-#panic-rtt-target = { version = "0.1.2", features = ["cortex-m"] }
+# rtt-target = "0.5.0"
+# panic-rtt-target = "0.1.3"
 
 [dev-dependencies]
 # Sneak in dependencies for examples which clash with panic-hal when generating
 # docs with rustdoc.
-rtt-target = { version = "0.3.1", features = ["cortex-m"] }
-panic-rtt-target = { version = "0.1.2", features = ["cortex-m"] }
+rtt-target = "0.5.0"
+panic-rtt-target = "0.1.3"
 
 [features]
 v2 = ["microbit-v2"]