Remove Python 3.6 support (#183)

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
       fail-fast: false
       max-parallel: 3
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2

matador/__init__.py

@@ -7,28 +7,10 @@
 theory compute engines.
 """
 
-import sys
-
 
 __all__ = ['__version__']
 __author__ = 'Matthew Evans'
 __maintainer__ = 'Matthew Evans'
 __version__ = "0.9.11"
 
 script_epilog = f"Written and maintained by Matthew Evans (me388@cam.ac.uk) 2016-2021, version {__version__}."
-
-if sys.version_info.minor == 6:
-    # Python 3.6
-    import warnings
-
-    warnings.filterwarnings(
-        action="once",
-        message=r"v0\.9.x of the `matador-db` package.*",
-        category=DeprecationWarning,
-        append=False,
-    )
-    warnings.warn(
-        "v0.9.x of the `matador-db` package will be the last to support Python 3.6. "
-        "Please upgrade to Python 3.7+ to use v0.10 and later versions of `matador-db`.",
-        DeprecationWarning,
-    )

setup.py

@@ -49,7 +49,6 @@
           "Intended Audience :: Science/Research",
           "License :: OSI Approved :: MIT License",
           "Programming Language :: Python :: 3",
-          "Programming Language :: Python :: 3.6",
           "Programming Language :: Python :: 3.7",
           "Programming Language :: Python :: 3.8",
           "Programming Language :: Python :: 3.9",