The highlight of this release is the support of per-app memory and CPU
isolators. This means that, in addition to restricting a pod’s CPU and memory
usage, individual apps inside a pod can also be restricted now.

rkt 0.6.1 also includes a new CLI/subcommand framework, more functional testing
and journalctl integration by default.

Notes:

• Due to changes in the spec ACIs generated with old versions of it might need to be rebuilt.
• As a consequence of using the new CLI/subcommand framework, long forms of command line options have to be prefixed by -- and, if they receive an argument, it should be separated from the option with =. For example: use --foo=bar instead of --foo bar or -foo=bar.

Full changelog:

• Updated to v0.6.1 of the appc spec
• support per-app memory and CPU isolators
• allow network selection to the --private-net flag which can be useful for
  grouping certain pods together while separating others
• move to the Cobra CLI/subcommand framework
• per-app logging via journalctl now supported by default
• stage1 runs an unpatched systemd v220
• to help packagers, rkt can generate stage1 from the binaries on the host at
  runtime
• more functional tests
• bugfixes