Added main script that allows for Calendar integration, and misc. changes

[LaRuim]

#29
@souravtecken

This is a major commit, as a few changes overall were needed to facilitate the making of the main script.

1. Created a main script called run.py. This fetches events from the Google Calendar, calls the appropriate scraper and does all the File I/O operations. It also has functions to update the database.

2. Altered db_tools.py slightly to allow each function to be called from run.py

3. Altered processor.py slightly to perform its task via the process method, to allow it to be called from run.py

4. Removed unnecessary commented code and added explanatory comments over all files.

5. Slightly altered the way logging is used over the entire project, standardizing it.

6. Edited the README to reflect the changes in the way the project is structured.

7. Edited requirements.txt to reflect dependencies better

To-do:

1. Make HackerRank and Google scrapers compatible with the main script.
2. Create a method to update README in the database folder after scraping.
3. More error handling
4. ?

Fixes #29