Need to add License File

[lykinsbd]

@tbotnz

This was talked about briefly in #cisshgo channel on networktocode.slack.com some time ago, but that is now lost to the ages and short scrollback of free slack.

We need to add a license file to this repo to define the license we're using.

https://choosealicense.com/ was what we looked at, I think we wanted to do the Lesser GPL v3:

https://choosealicense.com/licenses/lgpl-3.0/

Permissions

• Commercial use
• Distribution
• Modification
• Patent use
• Private use

Conditions

• Disclose source
• License and copyright notice
• Same license (library)
• State changes

Limitations

• Liability
• Warranty

If you're good with this, I can PR up the LGPL license file.

[tbotnz]

sounds good @lykinsbd