Relax source-location annotation validation

[joncfoo]

Problem

Some links that we use do not have a trailing slash at the end. Adding the trailing slash to these URLs results in a 404.

Solution

Remove the required trailing slash at the end of the source-location validator for non-directory locations. This allows us to use locations like url:http://some/where/else.

[Xantier]

Thanks @joncfoo . I'll merge this in and create a new package/action/org out of these changes shortly.

[Xantier]

This is now released under version number 0.2.7.

[joncfoo]

Thank you 😄