Replacing relative paths with absolute ones in generated critical CSS

[amorphine]

Discussing here
I'm not an experienced js-developer but I think the code could be usefull to enspire you to release the most reliable fix on your own.
It replaces relative paths with absolute ones based on css file location.
Thanks

[gajus]

Without the test cases it is not clear what the code is doing.

[coveralls]

Coverage decreased (-2.9%) to 87.156% when pulling d039432 on amorphine:feature into e6ecc83 on gajus:master.

[coveralls]

Coverage decreased (-2.9%) to 87.156% when pulling d039432 on amorphine:feature into e6ecc83 on gajus:master.

[coveralls]

Coverage increased (+0.3%) to 90.367% when pulling acb15b2 on amorphine:feature into e6ecc83 on gajus:master.

[coveralls]

Coverage increased (+0.3%) to 90.367% when pulling 6c02a22 on amorphine:feature into e6ecc83 on gajus:master.

[coveralls]

Coverage increased (+0.3%) to 90.367% when pulling 6c02a22 on amorphine:feature into e6ecc83 on gajus:master.