Introduce a few user arguments

lib/commands/sign.js

@@ -13,6 +13,10 @@ module.exports.builder = (yargs) => {
             describe: 'Challenge to sign',
             type: 'string'
         })
+        .option('p', {
+            describe: 'will post signature to response endpoint',
+            type: 'boolean'
+        })
         .demandOption(['challenge'])
         .argv;
 }

lib/core/logic/authentication.js

@@ -50,10 +50,12 @@ module.exports.authenticate = function(challenge, authenticationRequest, argv) {
                         const signature = cryptoUtil.signMessage(walletXpriv, challengeDerivationPath, challenge.message).toString('hex');
                         console.log("Signature: ", signature);
 
+                        if(argv.p) {
                             postSignature.postSignature(authenticationRequest.responseEndpoint, {
                                 id: challenge.id,
                                 signature: signature
                             })
+                        }
                     } else {
                         console.error("Challenge not signed by registered service.");
                     }