Drop TravisCI integration

All CI has been migrated over to Kubernetes test-infra.

.travis.yml

@@ -1,34 +0,0 @@
-language: go
-go:
-  - "1.14.7"
-
-env:
-  global:
-    # Sanitize git branch name into a valid docker tag name
-    - IMAGE_TAG_NAME=$(echo -n $TRAVIS_BRANCH | tr -c "[a-zA-Z0-9._'" "_")
-    - GO111MODULE=on
-
-services:
-  - docker
-
-script:
-  - scripts/test-infra/verify.sh
-  - scripts/test-infra/build-image.sh
-  - if [ "$TRAVIS_BRANCH" == master -a -n "$IMAGE_REPO_USER" ]; then
-      set -e;
-      echo "$IMAGE_REPO_PASSWORD" | docker login -u "$IMAGE_REPO_USER" --password-stdin quay.io;
-      make push -e;
-      scripts/test-infra/test-e2e.sh;
-    fi
-
-deploy:
-  - on:
-      branch: master
-      condition: -n "$IMAGE_REPO_USER"
-    provider: script
-    script: echo "$IMAGE_REPO_PASSWORD" | docker login -u "$IMAGE_REPO_USER" --password-stdin quay.io && make push -e
-  - on:
-      tags: true
-      condition: -n "$IMAGE_REPO_USER"
-    provider: script
-    script: echo "$IMAGE_REPO_PASSWORD" | docker login -u "$IMAGE_REPO_USER" --password-stdin quay.io && make push -e

README.md

@@ -1,6 +1,5 @@
 # Node feature discovery for [Kubernetes](https://kubernetes.io)
 
-[![Build Status](https://api.travis-ci.org/kubernetes-sigs/node-feature-discovery.svg?branch=master)](https://travis-ci.org/kubernetes-sigs/node-feature-discovery)
 [![Go Report Card](https://goreportcard.com/badge/github.com/kubernetes-sigs/node-feature-discovery)](https://goreportcard.com/report/github.com/kubernetes-sigs/node-feature-discovery)
 [![Prow Build](https://prow.k8s.io/badge.svg?jobs=pull-node-feature-discovery-build-image)](https://prow.k8s.io/job-history/gs/kubernetes-jenkins/pr-logs/directory/pull-node-feature-discovery-build-image)