Migrate pygmt.config tests to dvc

[seisman]

Description of proposed changes

Related to #1131.

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If adding new functionality, add an example to docstrings or tutorials.

Slash Commands

You can write slash commands (/command) in the first line of a comment to perform
specific operations. Supported slash commands are:

• /format: automatically format and lint the code
• /test-gmt-dev: run full tests on the latest GMT development version

[github-actions]

Summary of changed images

This is an auto-generated report of images that have changed on the DVC remote

Status	Path
added	pygmt/tests/baseline/test_config.png
added	pygmt/tests/baseline/test_config_font_annot.png
added	pygmt/tests/baseline/test_config_font_one.png
added	pygmt/tests/baseline/test_config_format_time_map.png
added	pygmt/tests/baseline/test_config_map_annot_offset.png
added	pygmt/tests/baseline/test_config_map_grid_cross_size.png
added	pygmt/tests/baseline/test_config_map_grid_pen.png
added	pygmt/tests/baseline/test_config_map_tick_length.png
added	pygmt/tests/baseline/test_config_map_tick_pen.png

Image diff(s)

• pygmt/tests/baseline/test_config.png

• pygmt/tests/baseline/test_config_font_annot.png

• pygmt/tests/baseline/test_config_font_one.png

• pygmt/tests/baseline/test_config_format_time_map.png

• pygmt/tests/baseline/test_config_map_annot_offset.png

• pygmt/tests/baseline/test_config_map_grid_cross_size.png

• pygmt/tests/baseline/test_config_map_grid_pen.png

• pygmt/tests/baseline/test_config_map_tick_length.png

• pygmt/tests/baseline/test_config_map_tick_pen.png

Report last updated at commit fe300d9

[weiji14]

Thanks @seisman!