Change code style to black

.gitlab-ci.yml

docs/source/conf.py

examples/image_example.py

examples/matplotlib_example.py

plotid/__init__.py

plotid/create_id.py

plotid/plotoptions.py

plotid/publish.py

plotid/save_plot.py

plotid/tagplot.py

plotid/tagplot_image.py

plotid/tagplot_matplotlib.py

tests/runner_tests.py

tests/test_create_id.py

tests/test_plotoptions.py

tests/test_publish.py

tests/test_save_plot.py

tests/test_tagplot.py

tests/test_tagplot_image.py

tests/test_tagplot_matplotlib.py