Fix Version/s: 0.7.1
Replace ivy with maven-ant-tasks.
Three main reasons:
1. In order to deploy cassandra to maven central, we will need to use maven-ant-tasks anyway (as ivy does not generate correct poms)
2. In order to generate gpg signatures using ivy, we need to bootstrap a second ivy taskdef or use multiple <get> tasks to download bouncycastle. Maven-ant-tasks does not require this.
3. Allows consolidating the dependency information in one place. Rather than having duplication with the maven-ant-tasks for deploy to central