Use path/filepath package methods for file system path for windows compatibility

[Gofastasf]

path package methods are used for URL and unix specific paths and might cause error on windows. filepath methods are cross platform and more consistent with the code.

[vdachev-david]

Is that what causes #2839 ?

[Gofastasf]

Could be. But anyways using filepath method is the right way for file system operation. path package methods are for unix specific or url operation.