chore(build): remove travis.yml file (#97)

Since the build and CI has been moved to GitHub action, travis
no longer needed.

Signed-off-by: shubham <[email protected]>

README.md

@@ -1,6 +1,6 @@
 # Upgrade
 
-[![Build Status](https://travis-ci.org/openebs/upgrade.svg?branch=master)](https://travis-ci.org/openebs/upgrade)
+[![Build Status](https://github.com/openebs/upgrade/actions/workflows/build.yml/badge.svg)](https://github.com/openebs/upgrade/actions/workflows/build.yml)
 [![Go Report](https://goreportcard.com/badge/github.com/openebs/upgrade)](https://goreportcard.com/report/github.com/openebs/upgrade)
 [![codecov](https://codecov.io/gh/openebs/upgrade/branch/master/graph/badge.svg)](https://codecov.io/gh/openebs/upgrade)
 [![Slack](https://img.shields.io/badge/chat!!!-slack-ff1493.svg?style=flat-square)](https://kubernetes.slack.com/messages/openebs)

RELEASE.md

@@ -26,7 +26,7 @@ Once the release branch is created, changelog from `changelogs/unreleased` needs
 
 The format of the release tag is either "Release-Name-RC1" or "Release-Name" depending on whether the tag is a release candidate or a release. (Example: v1.12.0-RC1 is a GitHub release tag for the upgrade release build. v1.12.0 is the release tag that is created after the release criteria are satisfied by the upgrade builds.)
 
-Once the release is triggered, Travis build process has to be monitored. Once Travis build is passed images are pushed to docker hub and quay.io. Images can be verified by going through docker hub and quay.io. Also the images shouldn't have any high-level vulnerabilities.
+Once the release is triggered, github actions release workflow process has to be monitored. Once github actions release workflow is passed images are pushed to docker hub and quay.io. Images can be verified by going through docker hub and quay.io. Also the images shouldn't have any high-level vulnerabilities.
 
 Images for the different components are published at the following location:
 

ci/migrate/sanity.sh

@@ -26,7 +26,7 @@ if [ -z "${IMAGE_ORG}" ]; then
 fi
 
 # To test the sanity in different versioned branches 
-# and travis tags, get the travis version and corresponding
+# and release tags, get the release version and corresponding
 # image tags
 # Determine the current branch
 CURRENT_BRANCH=""

ci/upgrade/sanity.sh

@@ -19,7 +19,7 @@ set -ex
 
 sudo modprobe iscsi_tcp
 
-# To enable dev upgardes in travis
+# To enable dev upgardes in github action
 make upgrade-image.amd64
 
 # To test the sanity in different customized
@@ -30,7 +30,7 @@ if [[ "${IMAGE_ORG}" == "" ]]; then
 fi
 
 # To test the sanity in different versioned branches 
-# and travis tags, get the travis version and corresponding
+# and release tags, get the release version and corresponding
 # image tags
 # Determine the current branch
 CURRENT_BRANCH=""