fix, typo in Cargo.toml

Cargo.toml

@@ -19,7 +19,7 @@ panic-itm               = "0.4.1"
 nb                      = "0.1.2"
 
 [dependencies.cortex-m]
-verison         = "0.6.2"
+version         = "0.6.2"
 # features        = ["inline-asm"] # <- currently requires nightly compiler
 
 [dependencies.cortex-m-rt]