Bump nltk from 3.5 to 3.9 #41

	# credit to mwouts for this great tutorial!
	name: CI (pip)
	on:
	push:
	pull_request:
	pull_request_review:
	types: [edited]

	jobs:
	build:
	strategy:
	matrix:
	os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
	python-version: [3.7, 3.8]
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v2
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v1
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install -r requirements.txt
	pip install -r requirements-dev.txt
	# install black if available (Python 3.6 and above), and autopep8 for testing the pipe mode
	pip install black \|\| true
	pip install autopep8 \|\| true
	# install sphinx_gallery and matplotlib if available (may not work on pypy)
	pip install sphinx_gallery \|\| true
	- name: Lint with flake8
	run: \|
	# stop the build if there are Python syntax errors or undefined names
	flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
	# all Python files should follow PEP8 (except some notebooks, see setup.cfg)
	flake8 src tests --max-line-length=120
	# exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
	flake8 . --count --exit-zero --max-complexity=10 --statistics
	- name: Install the src packages
	run: pip install -e .
	- name: Test with pytest
	run: pytest --cov=./ --cov-report=xml
	- name: Upload coverage
	uses: codecov/codecov-action@v1

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