SDK auto-capture events

[azhard4int]

Problem

What problem this feature is going to solve. Why this problem is important

Right now, we need to send the events manually by using jitsu.track('event_name'). It is difficult to keep track for the events that are added to product and there is always a chance some of the events are missed while developing new feature in the product.

Solution

Proposed solution: architecture, implementation details etc

It would be really cool to have a feature where we can tell Jitsu to capture/track events automatically by using a boolean flag: autoCapture.

If the flag is enabled, there are two options we can go with:

1. Keep track of events by using the html tags that are allowed: such as button, a etc.
2. Capture all clicked events and send to the Jitsu. (This is what Heap is doing: https://heap.io/product/autocapture)

What do you think of this, we can send a PR for this.