feat: add support for Python 3.8 (#17)

Closes #16

Author: tseaver

noxfile.py

@@ -47,7 +47,7 @@ def default(session):
     )
 
 
-@nox.session(python=["2.7", "3.5", "3.6", "3.7"])
+@nox.session(python=["2.7", "3.5", "3.6", "3.7", "3.8"])
 def unit(session):
     """Default unit test session."""
     default(session)

setup.py

@@ -71,7 +71,8 @@
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
-        'Programming Language :: Python :: 3.7',
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
         "Operating System :: OS Independent",
         "Topic :: Internet",
     ],
@@ -80,7 +81,7 @@
     namespace_packages=namespaces,
     install_requires=dependencies,
     extras_require=extras,
-    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*',
+    python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*",
     include_package_data=True,
     zip_safe=False,
 )