Set the --deadline flag of golangci-lint to 5m.

Currently, the deadline is set to the defalut value (1m), which is too
short to finish the linters sometimes, and causes error:
	ERRO [runner] 0/12 linters finished: deadline exceeded
	ERRO Deadline exceeded: try increase it by passing --deadline option

Author: haiyanmeng

test.sh

@@ -123,6 +123,7 @@ golangci-lint run --disable-all \
     --enable=misspell \
     --enable=gocyclo \
     --enable=gosec \
+    --deadline=5m \
     ./pkg/... ./cmd/...
 
 # --enable=structcheck \  # doesn't understand embedded structs