Windows : disk letter in lower case and before_capture option

[ajoah]

Hi,

On Windows, the disk letter is not always uppercase. It could cause a bug with before_capture option.

Example:

My option :
before_capture: 'javascript/wait--casper.js'

I start cmd, the default path is C:\Users\my-user.
So i can enter this commands to go to the good path :

C:\Users\my-user> cd f:\project
C:\Users\my-user> f:
f:\project>wraith capture configs/spider.yaml`

This causes an error :
Can't find module f:/project/f:/project/javascript/wait--casper.js

It is because of the regex in convert_to_absolute function which wants an uppercase letter for the disk.

This PR modify the regex to accept a lowercase letter too.

[ChrisBAshton]

Thanks for the PR. This has now been released in v4.2.3.