Add functionality that allows for importing wakatime data into the dataset

[rphovley]

The new db schema for activities is a more trimmed down than wakatime's "heartbeats."

Requirements:

• Takes in a csv of wakatime heartbeats,
• Reads those heartbeats in and converts them into monitor-service activities
• Make all heartbeats as "WINDOW" activity types
• Don't record a wakatime category (like desiging, coding, etc...) multiple times per a 30 second interval. If there are say, 5 heartbeats for coding within a 30 second period, only record one of those heartbeats. To keep it simple, the start of those 30 second intervals can be an arbitrary 30 second window where you decide, or as measured out from the first heartbeat.