Resolve asset spec as path if a file exists with that path

[viningM]

Fixed the issue described here: #57
For file paths on windows, the path was treated as a package due to having a colon in it.

With the fix, any asset spec will first be checked to see if it is a local file path before being treated as a package.

[tilgovi]

Excellent! It's been a while since I looked at this repo, but this looks good. It would be nice to make sure it's covered by the test suite. If you can add a test, that'd be great. I'll take a look over the weekend and see if I can recommend any way to test it if it's not obvious to you.

[tilgovi]

Can you fix a couple things before I merge this, please?

1. We should return (None, item) rather than (__name__, item) because that's the signal that this string is not an asset spec and has no package part. When this happens, depending on why we were checking, we do things that this PR might break, such as calling the parent class to check relative paths in all the configured asset directories.

2. Sometimes, the file may not exist but it's still meant to be treated as a file. I'm not positive, but this could be the case if, for example, an absolute Windows file path is used as an output path. Instead of checking "isfile", I think we should check whether the start of the path ismount().

[viningM]

The first change you request results in a type error, which is why I went with name in the first place, as a hack-y workaround. I'm not sure how to avoid this.

The second change is implemented and pushed.

[coveralls]

Coverage decreased (-0.4%) to 91.284% when pulling 03fcc1a on viningM:master into 060b532 on sontek:master.

[tilgovi]

Hmm, there should be no type error. Other code paths return None as the first of that tuple, but I'll look into it.

Looking at your patch now, it's still not quite right. The ismount has to be called on the mount point, I think. I'm not on a windows machine right now, but I think ismount would only succeed for something like "C:" or "C:" or UNC mounts. The whole item is string, such as "package:path/to/asset" or "C:\static\path\to\asset", will not return True for ismount.

[viningM]

Unfortunately I'm out of time to poke at it, I'll leave to you to fix or ignore.

Best of luck