First pass at adding support for scaling in rand/randn.

[a3ahmad]

Motivation and Context

An attempt at addressing issue #135

How Has This Been Tested

Not yet, hoping to discuss effective strategies as part of the discussion about this PR.

Types of changes

Additional parameter to rand/randn

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• [X ] New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• [ x] My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• [ x] I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed.