feat(open): Throw on incorrect baudrate option (#1347)

This was causing a lot of issues, lets make it easier on people.

examples/socketio/index.js

@@ -18,7 +18,7 @@ const serialport = require('serialport');
 const SerialPort = serialport.SerialPort;
 
 const serial = new SerialPort('/dev/cu.usbmodem1411', {
-  baudrate: 9600,
+  baudRate: 9600,
   parser: SerialPort.parsers.byteLength(1)
 });
 

lib/serialport.js

@@ -123,6 +123,10 @@ function SerialPort(path, options, callback) {
     throw new TypeError(`"path" is not defined: ${path}`);
   }
 
+  if (settings.baudrate) {
+    throw new TypeError(`"baudrate" is an unknown option, did you mean "baudRate"?`);
+  }
+
   if (typeof settings.baudRate !== 'number') {
     throw new TypeError(`"baudRate" must be a number: ${settings.baudRate}`);
   }

test/serialport.js

@@ -95,6 +95,12 @@ describe('SerialPort', () => {
       }
     });
 
+    it('throws an error when given bad baudrate even with a callback', function() {
+      assert.throws(() => {
+        this.port = new SerialPort('/dev/exists', { baudrate: 9600 }, () => {});
+      });
+    });
+
     it('errors with a non number baudRate', function(done) {
       try {
         this.port = new SerialPort('/bad/port', { baudRate: 'whatever' });