perf: run pytest in parallel

Sample output:

  platform linux -- Python 3.10.9, pytest-7.2.1, pluggy-1.0.0
  rootdir: /home/ilyazub/Workspace/google-search-results-python
  plugins: parallel-0.1.1
  collected 48

  pytest-parallel: 8 workers (processes), 6 tests per worker (threads)

`py` dependency is used because pytest-parallel depends on it but
doesn't require 😕
kevlened/pytest-parallel#118

Co-authored-by: Dimitry <[email protected]>

Makefile

@@ -12,27 +12,31 @@ clean:
 	find . -type d -name "__pycache__" -delete
 	pip3 uninstall google_search_results
 
+create_env:
+	python -m venv .env
+	source .env/bin/activate
+
 install:
 	python3 -m pip install --upgrade pip
 	if [ -f requirements.txt ]; then pip3 install -r requirements.txt; fi
 
-lint:
+lint: build_dep
 	# stop the build if there are Python syntax errors or undefined names
 	flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
 	# exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
 	flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
 
 # Test with Python 3
-test:
-	pytest
+test: build_dep
+	pytest --workers auto --tests-per-worker auto
 
 # run example only 
 #  and display output (-s)
 example:
 	pytest -s "tests/test_example.py::TestExample::test_async"
 
 build_dep:
-	pip3 install -U setuptools pytest flake8
+	pip3 install -U setuptools pytest py pytest-parallel flake8
 
 # https://packaging.python.org/tutorials/packaging-projects/
 build: