go.mod: update logrus to v1.8.1

Newer versions contain fixes for recent Go versions, and this removes
the dependency on github.com/konsorten/go-windows-terminal-sequences

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

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

@@ -4,14 +4,12 @@ git:
   depth: 1
 env:
   - GO111MODULE=on
-go: [1.13.x, 1.14.x]
-os: [linux, osx]
+go: 1.15.x
+os: linux
 install:
   - ./travis/install.sh
 script:
-  - ./travis/cross_build.sh
-  - ./travis/lint.sh
-  - export GOMAXPROCS=4
-  - export GORACE=halt_on_error=1
-  - go test -race -v ./...
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then go test -race -v -tags appengine ./... ; fi
+  - cd ci
+  - go run mage.go -v -w ../ crossBuild
+  - go run mage.go -v -w ../ lint
+  - go run mage.go -v -w ../ test