Add support for Python 3.10 and 3.11, drop EOL 3.6

Author: hugovk

livereload/server.py

@@ -29,10 +29,7 @@
 
 import sys
 
-if sys.version_info >= (3, 7):
-    import errno
-else:
-    from os import errno
+import errno
 
 if sys.version_info >= (3, 8) and sys.platform == 'win32':
     import asyncio

setup.py

@@ -36,7 +36,7 @@ def version():
     ],
     license='BSD',
     include_package_data=True,
-    python_requires='>=3.6',
+    python_requires='>=3.7',
     classifiers=[
         'Development Status :: 4 - Beta',
         'Environment :: Console',
@@ -48,10 +48,11 @@ def version():
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
         'Programming Language :: Python :: 3 :: Only',
         'Programming Language :: Python :: Implementation :: CPython',
         'Programming Language :: Python :: Implementation :: PyPy',