use the go 1.10 build cache

Signed-off-by: Steve Kriss <steve@heptio.com>

hack/build.sh

@@ -61,7 +61,7 @@ if [[ "${GOOS}" = "windows" ]]; then
   OUTPUT="${OUTPUT}.exe"
 fi
 
-go build -i \
+go build \
     -o ${OUTPUT} \
     -installsuffix "static" \
     -ldflags "${LDFLAGS}" \

hack/test.sh

@@ -23,6 +23,5 @@ export CGO_ENABLED=0
 TARGETS=$(for d in "$@"; do echo ./$d/...; done)
 
 echo "Running tests:"
-go test -i -installsuffix "static" ${TARGETS}
 go test -installsuffix "static" -timeout 60s ${TARGETS}
 echo "Success!"