Add SVG logo

Test Plan: no tests

Reviewed By: akr@fb.com

Subscribers: ldbrandy, jonp, smarlow, akr, bnitka, jcoens

FB internal diff: D1381974
lint

Summary: From PR 5 on github

Test Plan: unit tests

Reviewed By: akr@fb.com

Subscribers: ldbrandy, jonp, smarlow, akr, bnitka, jcoens

FB internal diff: D1384641
Sync the readme.md with the code

Summary: from PR 4

Test Plan: unit tests

Reviewed By: akr@fb.com

Subscribers: ldbrandy, jonp, smarlow, akr, bnitka, jcoens

FB internal diff: D1384640