Wrap sphdistance

[willschlitzer]

This pull request wraps the gmt module sphdistance.

Fixes #

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

[weiji14]

Looks alright to me 😁

[seisman]

Looks good to me.

[maxrjones]

Sorry for the comment after merging, but I think this needs to be in 'operations on tabular data' rather than 'operations on grids'.

Also the 'table' parameter is missing from the docstring (#1479 (comment) is relevant here).

[willschlitzer]

Sorry for the comment after merging, but I think this needs to be in 'operations on tabular data' rather than 'operations on grids'.

Also the 'table' parameter is missing from the docstring (#1479 (comment) is relevant here).

I'll open a PR to fix it