Added brackets around IPv6 host address

#197
#201

Try to fix dependency issues

This gets rid of the activesupport dependency in the code. There are also some fixes to try to get this plugin to work with ruby 2.0.

Support kubeclient version 4

Add support for kubeclient version 4. This also gets rid of the dependency on activesupport, and should solve some of the recent issues with transitive dependency conflicts.

add support for ssl_partial_chain

• ssl_partial_chain - if ca_file is for an intermediate CA, or otherwise we do not have the root CA and want
  to trust the intermediate CA certs we do have, set this to true - this corresponds to
  the openssl s_client -partial_chain flag and X509_V_FLAG_PARTIAL_CHAIN (default: false)

By setting ssl_partial_chain true in your configuration, you can
avoid #163

deprecate use_journal - add lookup_from_k8s_field - detect input

Instead of the user having to specify what the source of the container logs are, journal or json-file, let the plugin automatically figure it out by default. If there are fields named CONTAINER_NAME and CONTAINER_ID_FULL and they match the correct pattern, assume this is a journald record. Otherwise, if the tag matches the k8s filename tag, assume this is a json-file/crio file record. Otherwise, if there are already kubernetes fields in the record like kubernetes.namespace_name, kubernetes.pod_name, etc. assume the user is providing the metadata explicitly. You can still use the use_journal true flag if absolutely necessary, but don't.

Fixes LruRedux not found problem

Fixes LruRedux not found problem