* Add a setup test for middleware/file
This fix adds a setup test for middleware/file so that there is
a basic coverage for the Corefile processing of middleware/file.
This fix is related to 308 (Will look into it).
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* middleware/file: use helper function for test
Fixup setup_test.go and use the test.TempFile function to make things
somewhat shorter.
Use clean up the use of testing.T in TempFile - it is not used.
Cleanup the errors and removed deadcode along the way. The leaves
some error laying around, mostly about commenting exported identifier.
We should look hard if those really are needed.
