Filter error about grunt-sass

[sindresorhus]

From the top of the readme:

Bugs with the output should be submitted on the libsass repo which is the actual compiler.

[HugoHeneault]

Woops. Sorry.

[joelanman]

Hi, sorry to reopen an old issue, but I'm getting this error, and it seems to have been fixed in libsass 7 months ago?

sass/libsass#72

EDIT: Sorry ignore that, chasing the issue further up, either node-sass or libsass

[sindresorhus]

@joelanman hmm, weird, I think node-sass which this task uses, uses a 3 month old version of libsass. Anyways, you need to bring it up on the node-sass issue tracker ;)

[HugoHeneault]

I fixed my problem by updating npm.
(using npm update --save if I remember).