As suggested on bug 1488805 it would be great to get mozversion to support more than just the version of Firefox. The mozversion equivalent in Python handles the following:

mozversion application_buildid: 20180905094656
mozversion application_changeset: d8c933c4bd25ab7bf6f53a8d9235577c6e517d01
mozversion application_display_name: Nightly
mozversion application_id: {ec8030f7-c20a-464f-9b0e-13a3a9e97384}
mozversion application_name: Firefox
mozversion application_remotingname: firefox
mozversion application_vendor: Mozilla
mozversion application_version: 64.0a1
mozversion platform_buildid: 20180905094656
mozversion platform_changeset: d8c933c4bd25ab7bf6f53a8d9235577c6e517d01
mozversion platform_version: 64.0a1

All this information can be read when parsing the application.ini file. If it's not present we should keep all the properties as None.

Also having a method to print out all the data would be good to have.