Drop python2 support. (#613)

.travis.yml

@@ -1,8 +1,6 @@
 language: python
 matrix:
   include:
-    - python: 2.7
-      env: TOX_ENV=py27
     - python: 3.5
       env: TOX_ENV=py35
     - python: 3.6

Makefile

@@ -65,7 +65,7 @@ coverage: $(ISSO_PY_SRC)
 	nosetests --with-doctest --with-coverage --cover-package=isso --cover-html isso/
 
 test: $($ISSO_PY_SRC)
-	python setup.py nosetests
+	python3 setup.py nosetests
 
 clean:
 	rm -f $(DOCS_MAN_DST) $(DOCS_CSS_DST) $(ISSO_JS_DST)

setup.py

@@ -8,8 +8,8 @@ from setuptools import setup, find_packages
 requires = ['itsdangerous', 'Jinja2', 'misaka>=2.0,<3.0', 'html5lib',
             'werkzeug>=1.0', 'bleach', 'flask-caching']
 
-if sys.version_info < (2, 7):
-    raise SystemExit("Python 2 versions < 2.7 are not supported.")
+if sys.version_info < (3, ):
+    raise SystemExit("Python 2 is not supported.")
 elif (3, 0) <= sys.version_info < (3, 4):
     raise SystemExit("Python 3 versions < 3.4 are not supported.")
 
@@ -30,16 +30,12 @@ setup(
         "Topic :: Internet :: WWW/HTTP :: HTTP Servers",
         "Topic :: Internet :: WWW/HTTP :: WSGI :: Application",
         "License :: OSI Approved :: MIT License",
-        "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6"
         "Programming Language :: Python :: 3.7"
         "Programming Language :: Python :: 3.8"
     ],
     install_requires=requires,
-    extras_require={
-        ':python_version=="2.7"': ['ipaddr>=2.1', 'configparser']
-    },
     setup_requires=["cffi>=1.3.0"],
     entry_points={
         'console_scripts':

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py35,py36,py37,py38
+envlist = py35,py36,py37,py38
 
 [testenv]
 deps =