Update library version to 2.7.11
diff --git a/ChangeLog b/ChangeLog
index f155a02..f177bdb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,6 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
-= mbed TLS 2.7.x branch released xxxx-xx-xx
+= mbed TLS 2.7.11 branch released 2019-06-11
 
 Security
    * Make mbedtls_ecdh_get_params return an error if the second key