This fix updates the Makefile to add the `go lint` check
for the build. This fix also fixes several go lint issues.

NOTE: This fix does not enforce `go lint` (suggestion only).
This fix also ignores the `go lint` error:
```
middleware/middleware.go:72:1: context.Context should be the first parameter of a function
```
as it requires too many changes in API.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>