chore: drop python 3.4 support

.circleci/config.yml

@@ -65,10 +65,6 @@ workflows:
       - linter/pre-commit:
           python_version: 3.7.5
 
-      - toxpy:
-          name: test-py3.4
-          docker_image: '3.4'
-          tox_environment: py34
       - toxpy:
           name: test-py3.5
           docker_image: '3.5'

.travis.yml

@@ -2,7 +2,6 @@ sudo: false
 
 language: python
 python:
-  - 3.4
   - 3.5
   - 3.6
   - 3.7

setup.py

@@ -39,9 +39,7 @@
     ],
     tests_require=['mock', 'pytest'],
     extras_require={
-        # N.B. PyYAML 5.3 dropped support for Python 3.4... which we should
-        # also do...
-        'yaml': ['PyYAML>=3.10,<5.3'],
+        'yaml': ['PyYAML>=3.10'],
     },
     classifiers=[
         'Development Status :: 5 - Production/Stable',
@@ -50,7 +48,6 @@
         'License :: OSI Approved :: MIT License',
         'Operating System :: OS Independent',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{34,35}-cov{41}-{default,pyyaml},py{36,37,38,py3}-cov{41,5}-{default,pyyaml}
+envlist = py35-cov41-{default,pyyaml},py{36,37,38,py3}-cov{41,5}-{default,pyyaml}
 
 [gh-actions]
 python =