chore: drop support for Python 3.5 (#3269)

- Bump Python version requirement to 3.6
- Update pypi package classifiers
- Update docs
- Update CI test runners and codecov config

.codecov.yml

@@ -3,7 +3,7 @@ codecov:
     require_ci_to_pass: true
     # wait until at all test runners have uploaded a report (see the test job's build matrix)
     # otherwise, coverage failures may be shown while some reports are still missing
-    after_n_builds: 10
+    after_n_builds: 8
 comment:
   # this also configures the layout of PR check summaries / comments
   layout: "reach, diff, flags, files"

.github/workflows/main.yml

@@ -21,7 +21,7 @@ jobs:
       # when changing the build matrix and changing the number of test runners
       matrix:
         os: [ubuntu-latest, windows-latest]
-        python: [3.5, 3.6, 3.7, 3.8, 3.9]
+        python: [3.6, 3.7, 3.8, 3.9]
 #       include:
 #         - python: X.Y-dev
 #           continue: true

docs/install.rst

@@ -295,7 +295,7 @@ To install Streamlink from source you will need these dependencies.
 ==================================== ===========================================
 Name                                 Notes
 ==================================== ===========================================
-`Python`_                            At least version **3.5**.
+`Python`_                            At least version **3.6**.
 `python-setuptools`_
 
 **Automatically installed by the setup script**

setup.py

@@ -87,7 +87,7 @@ setup(name="streamlink",
       entry_points=entry_points,
       install_requires=deps,
       test_suite="tests",
-      python_requires=">=3.5, <4",
+      python_requires=">=3.6, <4",
       classifiers=["Development Status :: 5 - Production/Stable",
                    "License :: OSI Approved :: BSD License",
                    "Environment :: Console",
@@ -97,7 +97,6 @@ setup(name="streamlink",
                    "Operating System :: MacOS",
                    "Programming Language :: Python :: 3",
                    "Programming Language :: Python :: 3 :: Only",
-                   "Programming Language :: Python :: 3.5",
                    "Programming Language :: Python :: 3.6",
                    "Programming Language :: Python :: 3.7",
                    "Programming Language :: Python :: 3.8",