Refactor parser

[woile]

1. Move all the HTML Parsers to it's own class.
2. Refactor insta_scrapper.py to use the Parser instead of trying directly to retrieve a comment.
3. Create a new api_tests and write tests for Parser to be run manually
4. Ignore scrapper from coverage.

e.g: Instead of doing

@property
    def _is_followed(self):
        """Use only after getting a post page somewhere else."""
        button = self.find('xpath', const.FOLLOW_UNFOLLOW_BUTTON, wait=False)
        return button.text == 'Following'

We should do:

@property
    def _is_followed(self):
        """Use only after getting a post page somewhere else."""
        button = self.parser.follow_button()
        return button.text == 'Following'

[emilppp]

We're a group at KTH (https://www.kth.se/en) and would like to help you with this issue

[woile]

Be my guest @emilppp. We are more than glad to receive PR. Are the requirements clear enough?

[emilppp]

Turns out that unfortunately your project is considered too 'small' for us in this course : - ( The requirements/documentation is spot on tho!