Vendored version of logrus uses incorrect import path

[gcmurphy]

The current way in which Logrus is vendored in this project breaks the new golang.org dep tool (see for more details: golang/dep#1738).

The issue: the vendored version is github.com/Sirupsen/logrus and it should be github.com/sirupsen/logrus.

From the Logrus README:

Seeing weird case-sensitive problems? It's in the past been possible to import Logrus as both upper- and lower-case. Due to the Go package environment, this caused issues in the community and we needed a standard. Some environments experienced problems with the upper-case variant, so the lower-case was decided. Everything using logrus will need to use the lower-case: github.com/sirupsen/logrus. Any package that isn't, should be changed.

For more details:
sirupsen/logrus#570 (comment)

Is it possible to correct your vendored dependencies?

[jvehent]

All taken care of :)

[gcmurphy]

I had pretty much this exact PR waiting but cool thanks...