Migrate to clap v3.0.0

This patch replaces structopt with clap v3.0.0.

Author: robinkrahl

Cargo.lock

@@ -40,6 +40,14 @@ version = "1.0"
 [dependencies.base32]
 version = "0.4.0"
 
+[dependencies.clap]
+version = "3.0.0-rc.0"
+default-features = false
+features = ["derive", "std", "unicode"]
+
+[dependencies.clap_generate]
+version = "3.0.0-rc.0"
+
 [dependencies.directories]
 version = "3"
 

Cargo.toml

@@ -23,7 +23,7 @@ macro_rules! Command {
     $( $(#[$doc:meta])* $var:ident$(($inner:ty))? => $exec:expr, ) *
   ] ) => {
     $(#[$docs])*
-    #[derive(Debug, PartialEq, structopt::StructOpt)]
+    #[derive(Debug, PartialEq, clap::StructOpt)]
     pub enum $name {
       $(
         $(#[$doc])*