Add participants geolocation to data model

**Description**
A way to get participants’ geolocation is important for any org to show its global influence, this can be used for map display and statistics.

**Purpose**
To show how people from different regions can together join open source projects and make the project great together so more people might be encouraged. Moreover, it can strengthen the local bond in open source project development. It can also serve for statistical purposes.

**Implementation**
To acquire all geolocation of participants, we can use the following procedure:

Names(from google) -> Github account -> Location(curl -i https://api.github.com/users/grox-ni/location) -> Recognization(with some external API to recognize geolocation from string).->Display(e.g. D3.js)

Anyone who wants to can disclose their approx geolocation on GitHub as a string, and it can be converted to geo coords.