Remove redundant get_* functions in repo_processor

[snehasi]

Solves #36

Added get_repo_file(repo_url, file_name, file_type, post_func=None)

Introduced two more arguments file_type and post_func

• file_type is used for determining location of file in .temp folder - having this argument allows for flexibility with file_name in repos
• post_func is reference to a function that is applied to the file after its download.

Also added get_file_location function to generate file location from file_type.

Would appreciate reviews.

Thanks!

[maany]

Cool, I'll review this tomorrow. 👍