reflected exclude option when use glob

[sh4869]

When use --exclude option and glob pattern (ex: test/**.py) , exclude option is not reflected. I think exclude option should be reflected when specify files as same as specify folder.

[coveralls]

Coverage increased (+0.006%) to 99.537% when pulling 1ef0fb1 on sh4869:fix/exlucde-on-glob into 9fe7aae on myint:master.

[myint]

Sounds good to me.

Please add a unit test for this functionality. Thanks!

[sh4869]

I added a unit test for is_exclude_file.