add password hashing function + easier prod

src/server/backend/credentials/pwdmanager.js

@@ -24,4 +24,10 @@ module.exports.checkpassword = function checkpassword ( email, password ) {
             } );
         } );
     } );
+};
+
+module.exports.hashPassword = ( password ) => {
+    return new Promise( resolve => {
+        resolve( bcrypt.hashSync( password, 10 ) );
+    } );
 };