travis: fix functional tests

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

.travis.yml

@@ -45,10 +45,10 @@ script:
         GOARCH=amd64 CPU=4 PASSES='integration' ./test
         ;;
       linux-amd64-functional)
-        GOARCH=amd64 PASSES='functional' ./test
+        ./build && GOARCH=amd64 PASSES='functional' ./test
         ;;
       linux-amd64-unit)
-        GOARCH=amd64 PASSES='unit' ./test
+        ./build && GOARCH=amd64 PASSES='unit' ./test
         ;;
       linux-amd64-e2e)
         GOARCH=amd64 PASSES='build release e2e' MANUAL_VER=v3.3.13 ./test
@@ -61,6 +61,6 @@ script:
           && GO_BUILD_FLAGS='-v' GOARCH=ppc64le ./build
         ;;
       linux-386-unit)
-        GOARCH=386 PASSES='unit' ./test
+        GOARCH=386 ./build && GOARCH=386 PASSES='unit' ./test
         ;;
     esac