Fix error in deleting patterns due to non empty directory

[sherif-fanous]

What this Pull Request (PR) does

A Fabric pattern is made up of a directory in ~/.config/fabric/patterns where the name of the directory represents the pattern name. Within that directory are one or more .md files that describe the pattern.

With the current implementation that uses os.Remove, invoking the DELETE /patterns/:name API results in the following error

"could not delete test: remove /Users/sherif/.config/fabric/patterns/test: directory not empty"

since os.Remove will only delete files or empty directories.

This PR replaces os.Remove with os.RemoveAll that deletes the specified path and any children it contains

This ensures that patterns can be deleted whilst also maintaining functionality of being able to delete entities such as contexts/sessions

[ksylvan]

I don't like the proposed behavior.

If Fabric finds something in the patterns directory that it didn't expect, it must have been created and placed there by the user, so it seems right for Fabric to fail with a helpful error message.

The user can then decide what to do with what they placed in the patterns/ directory and try again.

[ksylvan]

I'm revising my thinking. If we assume that the API request is valid and authorized, then it should be okay to assume the user really wants to delete that pattern.

[sherif-fanous]

I understand the concern in case a user stores files unrelated to a pattern in a pattern directory.

With that said the current DELETE pattern API is technically of no use.

If the user will have to manually delete the files in the directory then why would they then use the API to delete the pattern directory?

I'd just do rm -fr ~/.config/fabric/patterns/test instead of going through the hassle of rm ~/.config/fabric/patterns/test/* then invoking the API

[ksylvan]

With that said the current DELETE pattern API is technically of no use.

Agreed.