workflows: Remove TRAVIS variables

These are not used any longer.

Fixes: kata-containers/kata-containers#3544
Signed-off-by: Jeremi Piotrowski <jpiotrowski@microsoft.com>

Author: Jeremi Piotrowski

.github/workflows/main.yml

@@ -5,21 +5,11 @@ jobs:
     runs-on: ubuntu-20.04
     env:
       GO111MODULE: off
-      TRAVIS: "true"
-      TRAVIS_BRANCH: ${{ github.base_ref }}
-      TRAVIS_PULL_REQUEST_BRANCH: ${{ github.head_ref }}
-      TRAVIS_PULL_REQUEST_SHA: ${{ github.event.pull_request.head.sha }}
     steps:
     - name: Install Go
       uses: actions/setup-go@v2
       with:
         go-version: "1.16"
-    - name: Setup GOPATH
-      run: |
-        echo "TRAVIS_BRANCH: ${TRAVIS_BRANCH}"
-        echo "TRAVIS_PULL_REQUEST_BRANCH: ${TRAVIS_PULL_REQUEST_BRANCH}"
-        echo "TRAVIS_PULL_REQUEST_SHA: ${TRAVIS_PULL_REQUEST_SHA}"
-        echo "TRAVIS: ${TRAVIS}"
     - name: Checkout code
       uses: actions/checkout@v2
       with:
@@ -29,9 +19,6 @@ jobs:
       run: |
         echo "GOPATH=${{ github.workspace }}" >> $GITHUB_ENV
         echo "${{ github.workspace }}/bin" >> $GITHUB_PATH
-    - name: Setup travis references
-      run: |
-        echo "TRAVIS_BRANCH=${TRAVIS_BRANCH:-$(echo $GITHUB_REF | awk 'BEGIN { FS = \"/\" } ; { print $3 }')}" 
     - name: Setup
       run: |
         ci_repo=$(go env GOPATH)/src/github.com/kata-containers/ci