Drop support for EOL Python 2.7 and 3.4-3.5

Author: hugovk

.github/workflows/tests.yml

@@ -12,11 +12,11 @@ on:
 jobs:
   test:
     name: "Python ${{ matrix.python-version }} ${{ matrix.name-suffix }}"
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
 
     strategy:
       matrix:
-        python-version: ["2.7", "3.5", "3.6", "3.7", "3.8", "3.9"]
+        python-version: ["3.6", "3.7", "3.8", "3.9"]
 
     steps:
       - uses: actions/checkout@v2

appveyor.yml

@@ -5,12 +5,6 @@ image: Visual Studio 2019
 
 environment:
   matrix:
-     - PYTHON: "C:\\Python27"
-     - PYTHON: "C:\\Python27-x64"
-     - PYTHON: "C:\\Python34"
-     - PYTHON: "C:\\Python34-x64"
-     - PYTHON: "C:\\Python35"
-     - PYTHON: "C:\\Python35-x64"
      - PYTHON: "C:\\Python36"
      - PYTHON: "C:\\Python36-x64"
      - PYTHON: "C:\\Python37"

setup.py

@@ -9,18 +9,15 @@
       url='https://github.com/matplotlib/cycler',
       platforms='Cross platform (Linux, Mac OSX, Windows)',
       license="BSD",
-      python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
+      python_requires='>=3.6',
       classifiers=['License :: OSI Approved :: BSD License',
                    'Development Status :: 4 - Beta',
-                   'Programming Language :: Python :: 2',
-                   'Programming Language :: Python :: 2.7',
                    'Programming Language :: Python :: 3',
-                   'Programming Language :: Python :: 3.4',
-                   'Programming Language :: Python :: 3.5',
                    'Programming Language :: Python :: 3.6',
                    'Programming Language :: Python :: 3.7',
                    'Programming Language :: Python :: 3.8',
                    'Programming Language :: Python :: 3.9',
+                   'Programming Language :: Python :: 3 :: Only',
                    ],
       keywords='cycle kwargs',
       )