remove unused import

Author: aoberoi

src/main/java/com/opentok/OpenTok.java

@@ -15,7 +15,6 @@
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.type.TypeFactory;
 import com.opentok.exception.OpenTokException;