travis: do not run functional for now

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>

.travis.yml

@@ -19,7 +19,6 @@ env:
   matrix:
   - TARGET=linux-amd64-integration-1-cpu
   - TARGET=linux-amd64-integration-4-cpu
-  - TARGET=linux-amd64-functional
   - TARGET=linux-amd64-unit
   - TARGET=linux-amd64-e2e
   - TARGET=all-build
@@ -44,9 +43,6 @@ script:
       linux-amd64-integration-4-cpu)
         GOARCH=amd64 CPU=4 PASSES='integration' ./test
         ;;
-      linux-amd64-functional)
-        GOARCH=amd64 PASSES='functional' ./test
-        ;;
       linux-amd64-unit)
         GOARCH=amd64 PASSES='unit' ./test
         ;;