Prevent compile error if /priv/static/svg doesn't exist

[johantell]

If /priv/static/svg doesn't exist the compile step causes an error preventing a lot of things from happening.

This fix will prevent that error and instead "fail" silently by not creating cached methods for assets

[coveralls]

Coverage remained the same at 0.0% when pulling 2c854e2 on mintcore:fix/compile_error_on_missing_folder into f025f57 on nikkomiu:master.

[johantell]

Credo doesn't seem to like that extra level the case statement adds. As I cannot get past that without refactoring. Would it be ok if i refactored the __using__ method and extracted some things?

[nikkomiu]

Thanks for the pull request!

I think it would look a lot better with a refactor of __using__ it is getting pretty deep with the added case.

[coveralls]

Coverage remained the same at 0.0% when pulling c1b7b58 on mintcore:fix/compile_error_on_missing_folder into f025f57 on nikkomiu:master.

[coveralls]

Coverage remained the same at 0.0% when pulling 8a3532a on mintcore:fix/compile_error_on_missing_folder into f025f57 on nikkomiu:master.

[johantell]

Would that be good enough?

[nikkomiu]

I want to double check that splitting this into multiple functions isn't going to break releases with Distillery before merging.

I think at one point I tried to split it into multiple functions and the result was the caching part didn't actually work.