Circonus

+++++++++++++++++++

**Improvements**

- Rename ``circonus.collectd.network`` to ``circonus.collectd.interface`` to
reflect what the name of the ``collectd`` module is.

++++++++++++++++++

**Improvements**

- Add collectd network graph
- Add API documentation

++++++++++++++++++

**Improvements**

- Add collectd memory graph
- Add API documentation

**Bug fixes**

- Fix key error when looking for metrics in a check bundle that has none.
- Handle error state when sorting metrics. If there were less metrics than
suffixes to sort by the returned list would contain ``None`` values. Now an
empty list is returned.

++++++++++++++++++

**Improvements**

- Add initial support for collectd
- Add graph module
- Add metric module
- Add API documentation

++++++++++++++++++

**Improvements**

- Add optional common tags parameter to CirconusClient class for a cleaner way
to specify common tags on a given instance of the client.
- Update all docstrings to reStructuredText format with parameter and return
types.
- Add API documentation.

++++++++++++++++++

**Bug fixes**

- Fix documentation link