Update build status link, fix typo

Author: igrr

README.md

@@ -8,7 +8,7 @@ This project brings support for ESP8266 chip to the Arduino environment. ESP8266
 Starting with 1.6.4, Arduino allows installation of third-party platform packages using Boards Manager. We have packages available for Windows, Mac OS, and Linux (32 and 64 bit).
 
 - Install Arduino 1.6.5 from the [Arduino website](http://www.arduino.cc/en/main/software).
-- Start Arduino and open Perferences window.
+- Start Arduino and open Preferences window.
 - Enter ```http://arduino.esp8266.com/stable/package_esp8266com_index.json``` into *Additional Board Manager URLs* field. You can add multiple URLs, separating them with commas.
 - Open Boards Manager from Tools > Board menu and install *esp8266* platform (and don't forget to select your ESP8266 board from Tools > Board menu after installation).
 
@@ -25,7 +25,7 @@ Boards manager link: `http://arduino.esp8266.com/staging/package_esp8266com_inde
 Documentation: [Reference](http://arduino.esp8266.com/staging/doc/reference.html)
 
 
-### Building latest version from source [![Linux build status](http://img.shields.io/travis/igrr/Arduino.svg)](https://travis-ci.org/igrr/Arduino)
+### Building latest version from source [![Linux build status](https://travis-ci.org/esp8266/Arduino.svg)](https://travis-ci.org/igrr/Arduino)
 
 ```
 $ git clone https://github.com/esp8266/Arduino.git