Merge pull request #6444 from qboot/master

Upgrade pyyaml to 4.2b1

requirements.txt

@@ -16,7 +16,7 @@ paramiko==2.4.2
 pypiwin32==219; sys_platform == 'win32' and python_version < '3.6'
 pypiwin32==223; sys_platform == 'win32' and python_version >= '3.6'
 PySocks==1.6.7
-PyYAML==3.12
+PyYAML==4.2b1
 requests==2.20.0
 six==1.10.0
 texttable==0.9.1

setup.py

@@ -32,7 +32,7 @@ def find_version(*file_paths):
 install_requires = [
     'cached-property >= 1.2.0, < 2',
     'docopt >= 0.6.1, < 0.7',
-    'PyYAML >= 3.10, < 4',
+    'PyYAML >= 3.10, < 4.3',
     'requests >= 2.6.1, != 2.11.0, != 2.12.2, != 2.18.0, < 2.21',
     'texttable >= 0.9.0, < 0.10',
     'websocket-client >= 0.32.0, < 1.0',