Drop Python 2.6 support

.github/workflows/test.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
 
     steps:
       - uses: actions/checkout@v2

Jenkinsfile

@@ -3,7 +3,6 @@ def pys = [
     [name: 'Python 3.9',  docker: 'python:3.9-buster',  tox:'py39', main: false],
     [name: 'Python 3.8',  docker: 'python:3.8-buster',  tox:'py38', main: false],
     [name: 'Python 3.7',  docker: 'python:3.7-buster',  tox:'py37', main: false],
-    [name: 'Python 3.6',  docker: 'python:3.6-buster',  tox:'py36', main: false],
 ]
 
 properties([

README.md

@@ -72,7 +72,7 @@ are old enough to view them.
 ### Dependencies
 
 Since dosage is written in [Python](http://www.python.org/), a Python
-installation is required: Dosage needs at least Python 3.6. Dosage requires
+installation is required: Dosage needs at least Python 3.7. Dosage requires
 some Python modules from PyPI, so installation with `pip` is recommended.
 
 ### Using the Windows binary

setup.cfg

@@ -18,7 +18,6 @@ classifiers =
     Programming Language :: Python
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
@@ -41,7 +40,7 @@ install_requires =
     cached_property;python_version<'3.8'
     importlib_metadata;python_version<'3.8'
 include_package_data = true
-python_requires = >=3.6
+python_requires = >=3.7
 setup_requires =
     setuptools>=38.3.0
     setuptools_scm

tox.ini

@@ -1,9 +1,8 @@
 [tox]
-envlist = py36, py37, py38, py39, py310, flake8
+envlist = py37, py38, py39, py310, flake8
 
 [gh-actions]
 python =
-    3.6: py36
     3.7: py37
     3.8: py38
     3.9: py39
@@ -35,15 +34,15 @@ commands =
 [flake8]
 # we aim for 79, but this suppresses warnings for now...
 max-line-length = 100
-ignore = E127,E128,E241,FI12,FI14,FI15,FI50,FI51,FI53,FI54,FI55,W504
+ignore = E127,E128,E241,FI12,FI14,FI15,FI18,FI50,FI51,FI53,FI54,FI55,W504
 require-code = True
 no-accept-encodings = True
-min-version = 3.6
+min-version = 3.7
 
 # Duplicated for CodeClimate...
 [pep8]
 max-line-length = 100
-ignore = E127,E128,E241,FI12,FI14,FI15,FI50,FI51,FI53,FI54,FI55,W504
+ignore = E127,E128,E241,FI12,FI14,FI15,FI18,FI50,FI51,FI53,FI54,FI55,W504
 
 [pytest]
 filterwarnings = default