Make raccoon imports standardized

[ramey]

Problem

Raccoon's module name currently is raccoon instead of github.com/odpf/raccoon which is not according to standard go module names. As a result, all the packages are imported as raccoon/config, raccoon/metrics, or raccoon/server etc.

What is the impact?
Raccoon packages cannot be imported into any other package.

Which version was this found?
NA

Solution
change module name to github.com/odpf/raccoon and change all the internal imports likewise.