Add AnyIO to dependencies

https://anyio.readthedocs.io/en/stable/index.html
https://anyio.readthedocs.io/en/stable/testing.html
https://anyio.readthedocs.io/en/stable/fileio.html
https://github.com/encode/starlette/releases/tag/0.15.0

AnyIO provides tools for asynchronous Python operations.
To start, AnyIO will be used for asyncio support with pytest.
The file I/O features may also be used when loading .env files.
Of note, AnyIO is the first external dependency for Starlette.

AnyIO will be an optional dependency, so the GitHub Actions workflow
will be updated to ensure that it is installed.

.github/workflows/ci.yml

@@ -44,14 +44,14 @@ jobs:
           python install-poetry.py -y
           echo "$POETRY_HOME/bin" >> $GITHUB_PATH
       - name: Install dependencies
-        run: poetry install --no-interaction
+        run: poetry install --no-interaction -E all
       - name: Run pre-commit hooks
         run: poetry run pre-commit run --all-files
       - name: Run unit tests
         run: poetry run pytest --cov-report=xml
       - name: Upload test coverage report to Codecov
         uses: codecov/codecov-action@v1
-        if: env.CODECOV_UPLOAD == 'true'
+        if: env.CODECOV_UPLOAD == 'true' && matrix.python-version == 3.9
         with:
           fail_ci_if_error: true
           flags: unit

pyproject.toml

@@ -37,6 +37,7 @@ classifiers = [
 
 [tool.poetry.dependencies]
 python = "^3.8"
+anyio = {version = "^3", optional = true}
 
 [tool.poetry.dev-dependencies]
 black = {version = "21.6b0", allow-prereleases = true}
@@ -49,6 +50,11 @@ pytest = "^6.2"
 pytest-cov = "^2.10"
 pytest-mock = "^3.3"
 
+[tool.poetry.extras]
+all = ["anyio"]
+anyio = ["anyio"]
+files = ["anyio"]
+
 [tool.pytest.ini_options]
 addopts = "--cov=fastenv -q"
 minversion = "6.0"