修改编译脚本、readme

README.md

 # 一个基于C++11简单易用的轻量级流媒体库
 平台|编译状态
 ----|-------
-Linux | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit.svg?branch=2.0-alpha)](https://travis-ci.org/xiongziliang/ZLMediaKit)
-macOS | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_mac.svg?branch=2.0-alpha)](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_mac)
-iOS | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit-build_for_ios.svg?branch=2.0-alpha)](https://travis-ci.org/xiongziliang/ZLMediaKit-build_for_ios)
-Android | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_android.svg?branch=2.0-alpha)](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_android)
+Linux | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit.svg?branch=master)](https://travis-ci.org/xiongziliang/ZLMediaKit)
+macOS | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_mac.svg?branch=master)](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_mac)
+iOS | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit-build_for_ios.svg?branch=master)](https://travis-ci.org/xiongziliang/ZLMediaKit-build_for_ios)
+Android | [![Build Status](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_android.svg?branch=master)](https://travis-ci.org/xiongziliang/ZLMediaKit_build_for_android)
 Windows | 已经完成移植
 
 ## 项目特点

build

+./mac_build
\ No newline at end of file

build_for_android.sh

@@ -7,7 +7,6 @@ cd $path
 cd ..
 git clone --depth=50 https://github.com/xiongziliang/ZLMediaKit.git
 cd ZLMediaKit
-git fetch origin 2.0-alpha:2.0-alpha
 mkdir -p android_build
 rm -rf ./build
 ln -s ./android_build build

build_for_linux.sh

@@ -13,7 +13,6 @@ cd $path
 cd ..
 git clone --depth=50 https://github.com/xiongziliang/ZLMediaKit.git
 cd ZLMediaKit
-git fetch origin 2.0-alpha:2.0-alpha
 mkdir -p linux_build
 rm -rf ./build
 ln -s ./linux_build build

build_for_mac.sh

@@ -12,7 +12,6 @@ cd $path
 cd ..
 git clone --depth=50 https://github.com/xiongziliang/ZLMediaKit.git
 cd ZLMediaKit
-git fetch origin 2.0-alpha:2.0-alpha
 mkdir -p mac_build
 rm -rf ./build
 ln -s ./mac_build build