Bump cortex-m-rt dev dependency to not create errors with stm32f0 0.14

Signed-off-by: Daniel Egger <[email protected]>

Author: therealprof

Cargo.toml

@@ -41,7 +41,7 @@ stm32-usbd = { version = "0.6", optional = true }
 bxcan = "0.4.0"
 
 [dev-dependencies]
-cortex-m-rt = "0.6"
+cortex-m-rt = "0.7"
 panic-halt = "0.2"
 usb-device = "0.2.7"
 usbd-serial = "0.1.1"