Require Python 3.5 or later, dropping support for Python 2.

This change does not yet remove any of the compatibility for Python 2, but only aims to declare the dropped support.

.travis.yml

@@ -4,14 +4,8 @@ language: python
 jobs:
   fast_finish: true
   include:
-  - &latest_py2
-    python: 2.7
-  - <<: *latest_py2
-    env: LANG=C
-  - python: pypy
-    env: DISABLE_COVERAGE=1  # Don't run coverage on pypy (too slow).
   - python: pypy3
-    env: DISABLE_COVERAGE=1
+    env: DISABLE_COVERAGE=1  # Don't run coverage on pypy (too slow).
   - python: 3.5
   - python: 3.6
   - python: 3.7

appveyor.yml

@@ -9,8 +9,8 @@ environment:
   matrix:
     - APPVEYOR_JOB_NAME: "python36-x64"
       PYTHON: "C:\\Python36-x64"
-    - APPVEYOR_JOB_NAME: "python27-x64"
-      PYTHON: "C:\\Python27-x64"
+    - APPVEYOR_JOB_NAME: "python37-x64"
+      PYTHON: "C:\\Python37-x64"
 
 install:
   # symlink python from a directory with a space

changelog.d/1458.breaking.rst

@@ -0,0 +1 @@
+Drop support for Python 2. Setuptools now requires Python 3.5 or later. Install setuptools using pip >=9 or pin to Setuptools <45 to maintain 2.7 support.

setup.cfg

@@ -35,8 +35,6 @@ classifiers =
     Intended Audience :: Developers
     License :: OSI Approved :: MIT License
     Operating System :: OS Independent
-    Programming Language :: Python :: 2
-    Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.5
     Programming Language :: Python :: 3.6
@@ -49,7 +47,7 @@ classifiers =
 
 [options]
 zip_safe = True
-python_requires = >=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*
+python_requires = >=3.5
 py_modules = easy_install
 packages = find: