Update Cargo.toml (#67)

* Update `defmt-rtt`

* Omit patch version from dependencies

* Format `Cargo.toml`

* Switch to rust 2021 edition

* Use `opt-level = 'z'` again

* Re-enable `lto`

Cargo.toml

@@ -2,7 +2,7 @@
 # TODO(1) fix `authors` and `name` if you didn't use `cargo-generate`
 authors = ["{{authors}}"]
 name = "{{project-name}}"
-edition = "2018"
+edition = "2021"
 version = "0.1.0"
 
 [lib]
@@ -14,16 +14,16 @@ name = "integration"
 harness = false
 
 [dependencies]
-cortex-m = "0.7.3"
+cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
-cortex-m-rt = "0.7.0"
+cortex-m-rt = "0.7"
-defmt = "0.3.0"
+defmt = "0.3"
-defmt-rtt = "0.3.0"
+defmt-rtt = "0.4"
-panic-probe = { version = "0.3.0", features = ["print-defmt"] }
+panic-probe = { version = "0.3", features = ["print-defmt"] }
 # TODO(4) enter your HAL here
 # some-hal = "1.2.3"
 
 [dev-dependencies]
-defmt-test = "0.3.0"
+defmt-test = "0.3"
 
 # cargo build/run
 [profile.dev]
@@ -31,7 +31,7 @@ codegen-units = 1
 debug = 2
 debug-assertions = true # <-
 incremental = false
-opt-level = 3 # <-
+opt-level = 'z'         # <-
 overflow-checks = true  # <-
 
 # cargo test
@@ -49,10 +49,7 @@ codegen-units = 1
 debug = 2
 debug-assertions = false # <-
 incremental = false
-# NOTE disabled to work around issue rust-lang/rust#90357
+lto = 'fat'
-# the bug results in log messages not having location information
-# (the line printed below the log message that contains the file-line location)
-# lto = 'fat'
 opt-level = 3            # <-
 overflow-checks = false  # <-
 
@@ -62,8 +59,7 @@ codegen-units = 1
 debug = 2
 debug-assertions = false # <-
 incremental = false
-# see comment in the profile.release section
+lto = 'fat'
-lto = false
 opt-level = 3            # <-
 overflow-checks = false  # <-