error: add CashierKeysNotFound error

src/error.rs

@@ -78,6 +78,7 @@ pub enum Error {
     /// Util
     ConfigNotFound,
     KeypairPathNotFound,
+    CashierKeysNotFound,
     SetLoggerError,
     AsyncChannelSenderError,
     AsyncChannelReceiverError,
@@ -143,6 +144,7 @@ impl fmt::Display for Error {
                 f.write_str("No config file detected. Please create a config file")
             }
             Error::KeypairPathNotFound => f.write_str("No keypair file detected."),
+            Error::CashierKeysNotFound => f.write_str("No cashier public keys detected."),
             Error::SetLoggerError => f.write_str("SetLoggerError"),
             Error::TokenParseError => f.write_str("Could not parse token parameter"),
             Error::TungsteniteError => f.write_str("TungsteniteError"),