Fixed accidental committed move and fixed unused functions warnings

The accidental commit took place in
3558a4869a. Modules were not declared public which caused warnings in these modules

src/main.rs

@@ -2,8 +2,8 @@
 //! 
 //! `footswitch-rs` enables you to use footswitches of <xxx>
 //! 
-mod key_operations;
-mod pedal_operations;
+pub mod key_operations;
+pub mod pedal_operations;
 
 #[macro_use]
 mod messages;