Drop support for Python 3.6

Author: duckontheweb

.github/workflows/continuous-integration.yml

@@ -20,7 +20,6 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"
@@ -140,9 +139,10 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.6"
           - "3.7"
           - "3.8"
+          - "3.9"
+          - "3.10.0-beta.3"
 
     steps:
       - uses: actions/checkout@v2

README.md

@@ -10,8 +10,13 @@ PySTAC is a library for working with [SpatialTemporal Asset Catalog](https://sta
 
 ## Installation
 
-PySTAC requires Python>=3.6. Support for Python>=3.10 should be considered experimental
-until further notice.
+PySTAC requires Python>=3.7. This project follows the recommendations of
+[NEP-29](https://numpy.org/neps/nep-0029-deprecation_policy.html) in deprecating support
+for Python versions. This means that users can expect support for Python 3.7 to be
+removed in next major or minor release after Dec 26, 2021.
+
+*Support for Python>=3.10 should be considered experimental
+until further notice.*
 
 PySTAC has a single required dependency (`python-dateutil`).
 PySTAC can be installed from pip or the source repository.

setup.py

@@ -22,7 +22,7 @@
     packages=find_packages(),
     py_modules=[splitext(basename(path))[0] for path in glob("pystac/*.py")],
     include_package_data=False,
-    python_requires=">=3.6",
+    python_requires=">=3.7",
     install_requires=[
         "python-dateutil>=2.7.0",
         'typing_extensions >= 3.7; python_version < "3.8"',
@@ -38,7 +38,6 @@
         "License :: OSI Approved :: Apache Software License",
         "Natural Language :: English",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",