Create SSL Certificate for SSL pinning

SSL pinning is a mechanism to ensure the application is talking to the "Real" server, and shouldn't susceptable to "Man in the Middle" attack.

Steps:

1. Get the original ssl certificate for the server
2. take the leaf certificate
3. attach it in the application

Getting SSL certificate

openssl s_client -servername dev.sunbirded.org -host dev.sunbirded.org -port 443 -showcerts

1. Check for the domain name, as highlighted above
2. copy from 
   

   -----BEGIN CERTIFICATE-----

   MIIGljCCBX6gAwIBAgIRAJU11K/RVD5pzOg+rvdI3IIwDQYJKoZIhvcNAQELBQAw

   gZAxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAO
   BgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBDQSBMaW1pdGVkMTYwNAYD
   VQQDEy1DT01PRE8gUlNBIERvbWFpbiBWYWxpZGF0aW9uIFNlY3VyZSBTZXJ2ZXIg
   Q0EwHhcNMTgxMjEwMDAwMDAwWhcNMTkxMjEwMjM1OTU5WjBiMSEwHwYDVQQLExhE
   .......
   ......
   .....
   

   -----END CERTIFICATE-----

3. save it as leaf.crt