Kryo exception for com.google.common.collect.RegularImmutableBiMap

[csashiuber]

Hi,
I am registering the [ImmutableMapSerializer](https://github.com/magro/kryo-serializers/blob/master/src/main/java/de/javakaffee/kryoserializers/guava/ImmutableMapSerializer.java) but get the following exception:

com.esotericsoftware.kryo.KryoException: Class cannot be created (missing no-arg constructor): com.google.common.collect.RegularImmutableBiMap

Is there a variation of ImmutableMap that we need to add to ImmutableMapSerializer.java?
Thank you!