v0.2.0 - Upgrade to Kubuilder 2.0 and Go Modules

Upgrade Notes

• An upgrade to the ZKOperator version 0.2.4 is required
• SolrCloud.zookeeperRef.provided.zookeeper.persistentVolumeClaimSpec has been deprecated in favor of the SolrCloud.zookeeperRef.provided.zookeeper.persistence option. This option is backwards compatible, but will be removed in a future version.
• Uses gomod instead of dep for dependency management

Bug Fixes

• Fixed status/solrPod reconciling loops.
  • If an ingress is used, the solr pods now use hostAliases to map the
    ingress URL of each solr node to the IP of the corresponding service
• Fixed a bug related to the first pod of the Solr StatefulSet starting
  without a zkConnectionString

New Features

• Added CollectionAlias CRD to manage aliases with SolrClouds & SolrCollections