Cc12703-uiautomator2

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* limit pure-python-adb version, to fix from adb.client import error
* support args

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* remove cmd:init from fire.Fire, fix forward error when muti device connect to one machine
* upgrade atx-agent
* ext\_xpath support
* remove 3.7
* fix travis test again
* fix travis
* sort imports
* split code to different files
* Update README.md
* Update README.md
* remove debug with dict: which will lead misunderstanding
* update atx-agent version
* appveyor
* exedir detection everywhere
* fix
* come at me
* need android components nowadays
* travis 2018 switches from android-21 to android-22
* fix pip install requirements
* fix travis lang
* add emulator and tests to travis and update README
* fix typo. (278)

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* fix connect\_usb init error, close 276
* fix typo
* add set\_fail\_prompt function
* add d.touch.(down|move|up) in readme
* fix atxagent version code

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* update atx-agent add api app\_info, and app\_icon
* update atx-agent version to 0.5.1, fix session timeout error
* update atx-agent version and netease music example
* add wait\_activity
* raise IndexError when UiObject returned by child\_by\_xxx, close 261
* fix xpath py2 py3 compatibale
* fix xpath ext resource-id error
* Update README.md (260)
* update weditor install method

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* sem-ver:bugfix, fix init with PATH env error on windows
* fix doc
* update apk to 1.1.7 to fix dumpHierarchy, close 207

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* use atx-agent server -stop before launch
* force stop atx-agent when init
* fix launch atx-agent with wrong PATH, which may cause /info get wrong info
* fix test on android P emulator
* 加入aricv图像识别插件 (250)
* update atx-agent version