Update .travis.yml

Author: grasmash

.travis.yml

@@ -84,11 +84,11 @@ deploy:
     skip_cleanup: true
     on:
       branch: $DEPLOY_SOURCE_BRANCH
-      php: 5.6
+      php: 7.1
   - provider: script
     # Deploys build artifact's source branch to acquia-pso/blted8 on GitHub.
     script: ${BLT_DIR}/scripts/blt/ci/internal/deploy_blted8.sh
     skip_cleanup: true
     on:
       branch: $DEPLOY_SOURCE_BRANCH
-      php: 5.6
+      php: 7.1