* Add common TLS config routines
These routines can be used to load TLS configs based upon the
args in the Corefile.
* Add common routine for Corefile arg handling
Add the NewTLSConfigFromArgs routine so that you can just pass
in the Corefile args and get a tls.Config. This ensures the
parameters are handled consistently across middleware.
* Change to varargs style params
Change to use args ...string instead of []string. Add
documentation of what each call means.
* 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.
