CLUSTER-81. Update pip package version to 2.0.4.

issue: https://jira.kiji.org/browse/CLUSTER-81
review: https://review.kiji.org/r/2252
over-the-shoulder-reviewers: afeldstein
CLUSTER-82. Fix incorrect return statement in _sudo_command that causes 'start' to fail.

issue: https://jira.kiji.org/browse/CLUSTER-82
review: https://review.kiji.org/r/2253
over-the-shoulder-reviewers: afeldstein