Godeps: Bump to urfave/cli v1.19.1 to get App.Description

This landed via [1] which was released with v1.19.0.  Bump to the most
recent release to get the .1 bugfixes too [2].  Generated with:

  $ godep update github.com/urfave/cli
  godep: WARNING: Godep workspaces (./Godeps/_workspace) are deprecated and support for them will be removed when go1.8 is released.
  godep: WARNING: Go version (go1.7) & $GO15VENDOREXPERIMENT= wants to enable the vendor experiment, but disabling because a Godep workspace (Godeps/_workspace) exists
  $ git add -A Godeps

[1]: urfave/cli#543
[2]: https://github.com/urfave/cli/blob/v1.19.1/CHANGELOG.md#1191---2016-11-21

Signed-off-by: W. Trevor King <[email protected]>

Author: wking