feature: adding imagex user and date features to .make file

## Ready State: (Yes)

This pull request is related to the following JIRA tickets: [LDC-230 Create panelized news article display page](https://imagex.atlassian.net/browse/LDC-230).

## Requirements & Dependencies

## Deployment Instructions

* No real deployment instructions. 

## Usage/Test Instructions

* when running imagex_installkit drush make, imagex_date and imagex_user should be cloned/checked out from git as well under profiles/imagex_installkit/modules/imagex/modules