Filter bots from contributors list

[jmuzina]

Currently there are several bot accounts that appear in our contributors list. Three of the contributors listed on our contributors page are bots, and renovate-bot appears in the top 10 contributors.

To better recognize human contributors, we should filter out bots from the contributors list.

We use this endpoint to fetch contributors. The current list of contributors can be seen here. Each user has a type attribute that can be User or Bot. We can filter out users with type=='Bot'. The exception is renovate-bot which, while being a bot, is not treated like a bot by Github as it has type='User'.