Update logrus to v1.6.0

Fixes #3223 by bumping logrus to v1.6.0, which in turn bumps
github.com/konsorten/go-windows-terminal-sequences to v1.0.3
wherein the fix to bad pointer is found.

Signed-off-by: Andreas Hassing <andreas@famhassing.dk>

vendor/github.com/sirupsen/logrus/.travis.yml

@@ -4,21 +4,13 @@ git:
   depth: 1
 env:
   - GO111MODULE=on
-  - GO111MODULE=off
-go: [ 1.11.x, 1.12.x ]
-os: [ linux, osx ]
-matrix:
-  exclude:
-    - go: 1.12.x
-      env: GO111MODULE=off
-    - go: 1.11.x
-      os: osx
+go: [1.13.x, 1.14.x]
+os: [linux, osx]
 install:
   - ./travis/install.sh
-  - if [[ "$GO111MODULE" ==  "on" ]]; then go mod download; fi
-  - if [[ "$GO111MODULE" == "off" ]]; then go get github.com/stretchr/testify/assert golang.org/x/sys/unix github.com/konsorten/go-windows-terminal-sequences; fi
 script:
   - ./travis/cross_build.sh
+  - ./travis/lint.sh
   - export GOMAXPROCS=4
   - export GORACE=halt_on_error=1
   - go test -race -v ./...