airtest 中，修改了图像识别阈值（THRESHOLD = 0.9，THRESHOLD_STRICT = 0.9），但是没有生效，在运行脚本的时候，阈值取得还是0.7
文件：AirtestIDE_2019-05-09_py3_win64\airtest\core\settings.py
内容修改：
class Settings(object):
DEBUG = False
LOG_DIR = None
LOG_FILE = "log.txt"
RESIZE_METHOD = staticmethod(cocos_min_strategy)
CVSTRATEGY = ["surf", "tpl", "brisk"] # keypoint matching: kaze/brisk/akaze/orb, contrib: sift/surf/brief
KEYPOINT_MATCHING_PREDICTION = True
THRESHOLD = 0.9 # [0, 1]
THRESHOLD_STRICT = 0.9 # [0, 1]
OPDELAY = 0.1
FIND_TIMEOUT = 20
FIND_TIMEOUT_TMP = 3
PROJECT_ROOT = os.environ.get("PROJECT_ROOT", "") # for ``using`` other script