Create .clabot (#64)

.clabot

@@ -0,0 +1,4 @@
+{
+  "contributors": "https://api.github.com/repos/OffchainLabs/clabot-config/contents/apache-contributors.json",
+  "message": "We require contributors to sign our Contributor License Agreement. In order for us to review and merge your code, please sign one of the linked documents below to get yourself added. If you're an independent Individual please sign this form: https://na3.docusign.net/Member/PowerFormSigning.aspx?PowerFormId=1353a816-a9c1-47ba-847e-ec79f0f23d31&env=na3&acct=6e152afc-6284-44af-a4c1-d8ef291db402&v=2. If you're with a company (corporate) please sign this form: https://na3.docusign.net/Member/PowerFormSigning.aspx?PowerFormId=2b5fe8ba-51d4-4980-b4ee-605d66e675d4&env=na3&acct=6e152afc-6284-44af-a4c1-d8ef291db402&v=2. To agree to the CLA license, please fill out one of the attached forms."
+}