GHA pretty env (#67)

* 🎨 Make the GHA log is clean and colorized

This patch sets up root-level environment variables shared by all the
workflow jobs. They include:

* Disabling undesired `pip`'s warnings/suggestions
* Requesting the executed apps color their output unconditionally
* Letting `tox` pass those requests to underlying/wrapped programs

* Reformat without end of line comments. Group into sections.

* Avoid numerics for booleans where possible. Choose arbitrary numeric where any numeric is accepted.

Co-authored-by: Sviatoslav Sydorenko <wk@sydorenko.org.ua>

.github/workflows/main.yml

@@ -2,6 +2,36 @@ name: tests
 
 on: [push, pull_request]
 
+env:
+  # Environment variables to support color support (jaraco/skeleton#66):
+  # Request colored output from CLI tools supporting it. Different tools
+  # interpret the value differently. For some, just being set is sufficient.
+  # For others, it must be a non-zero integer. For yet others, being set
+  # to a non-empty value is sufficient.
+  FORCE_COLOR: -106
+  # MyPy's color enforcement (must be a non-zero number)
+  MYPY_FORCE_COLOR: -42
+  # Recognized by the `py` package, dependency of `pytest` (must be "1")
+  PY_COLORS: 1
+  # Make tox-wrapped tools see color requests
+  TOX_TESTENV_PASSENV: >-
+    FORCE_COLOR
+    MYPY_FORCE_COLOR
+    NO_COLOR
+    PY_COLORS
+    PYTEST_THEME
+    PYTEST_THEME_MODE
+
+  # Suppress noisy pip warnings
+  PIP_DISABLE_PIP_VERSION_CHECK: 'true'
+  PIP_NO_PYTHON_VERSION_WARNING: 'true'
+  PIP_NO_WARN_SCRIPT_LOCATION: 'true'
+
+  # Disable the spinner, noise in GHA; TODO(webknjaz): Fix this upstream
+  # Must be "1".
+  TOX_PARALLEL_NO_SPINNER: 1
+
+
 jobs:
   test:
     strategy: