setup.py: drop python 3.5 support

Generates new python-support.svg with all supported python versions.
Add python 3.9 and 3.10 to the test matrix.

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.5', '3.6', '3.7', '3.8']
+        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
 
     steps:
     - uses: actions/checkout@v2

Makefile

@@ -74,4 +74,4 @@ bump-version:
 	./bump_version.py
 
 generate-badge:
-	$(VIRTUALENV)/bin/anybadge --value='3.5 | 3.6 | 3.7 | 3.8' --label python --file python-support.svg --overwrite
+	$(VIRTUALENV)/bin/anybadge --value='3.6 | 3.7 | 3.8 | 3.9 | 3.10' --label python --file python-support.svg --overwrite

README.rst

@@ -43,7 +43,7 @@ Dependencies
 
 The only dependencies are:
 
-- Python3.5+
+- Python3.6+
 - Linux kernel 2.6.24+
 - A libc that implements setns() and nsenter() (that’s basically any
   libc released after 2007)

setup.py

@@ -24,8 +24,8 @@
 from furnace.version import get_version
 
 
-if sys.version_info < (3, 5):
-    sys.exit('Python version 3.5+ is required for furnace')
+if sys.version_info < (3, 6):
+    sys.exit('Python version 3.6+ is required for furnace')
 
 with open(os.path.join(os.path.dirname(__file__), 'README.rst'), encoding='utf-8') as f:
     long_description = f.read()
@@ -52,5 +52,5 @@
     package_data={'furnace': [
         'VERSION',
     ]},
-    python_requires=">=3.5",
+    python_requires=">=3.6",
 )