Add license scan report and status

[fossabot]

Your FOSSA integration was successful! Attached in this PR is a badge and license report to track scan status in your README.

Below are docs for integrating FOSSA license checks into your CI:

• CircleCI
• TravisCI
• Jenkins
• Other

[fossabot]

Your license scan is passing -- congrats!

Your badge status is now updated and ready to merge:

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}