Release 0.15.7

Add better handling for null mac addresses

0.15.6

Use filter support from helium-python

0.15.5

Update CHANGES

0.15.4

Use device-type in sensor and element listings (#19)

0.15.3: Bumping dependency of helium-python

This picks up the removal of gevent which makes it a lot quicker to
install the package

0.15.2

Enables the --mac option for timeseries commands

0.15.1: Fix label creation.

The label POST endpoint on helium doesn't yet take sensors and
elements as part of creation, so we revert back to calling the update
methods as part of handling the command

0.15.0: Feature/label element (#17)

* Adds element support for labels

This adds support for managing elements as part of
labels. Adding/removing/replacing sensors and elements is now done in
the `label sensor` and `label element` commands and is no longer
supported in `label update`

* Update Changelog

0.14.0

Update Changelog for 0.14.0

0.13.2

Updating dependency to helium-python 0.6.4 to get in line with live t…