Updates README

Author: steve-perkins

README.md

@@ -231,6 +231,7 @@ should represent non-breaking changes.  The third number represents any very min
   * Adds "revoke-self" capability for auth tokens.  
   * Adds support for response-wrapping token validation 
   * Support for signing a new certificate based on a CSR (i.e. the `/v1/pki/sign` endpoint).
+  * Support for the PKI backend revoke method, and addition of a useCsrSans property in PKI role object
   * Gives `VaultConfig` the ability to disable loading from environment variables if desired.
   * Cleans up issues with the new Docker-based integration test suite.  
   * Updates all dependencies to their latest versions (including switching to Vault 0.9.1 for integration testing).