Building a heterogeneous dataset using the most active users

Let's build a heterogeneous dataset based on the public repositories created by the most active users of GitHub. As we know how to extract data using the package rgithub, we will explore the other method too, for example, directly using the API's URL. In this method, we need to pass the API URL to the function fromJSON, which has a dependency on the package jsonlite. The API URL will also work from the browser and will be checked for accuracy of the data. Those URLs will return data in JSON format.

The most active users of GitHub will be obtained through the following URL, or you can use the CSV file named TopUsers.csv, which also holds the data of users who were active as of July 2015. We will make use of the username to pull the additional data about the users.

Use the function read.csv to read the active users file from https://gist.github.com/paulmillr/2657075/ and read the username column as characters using the function as...