feat(splitter): chunking projectid, vaultid, start_marker and end_marker

This patch allows every vaultid specific to a projectid to be chunked
with a start marker and end marker. This allows the manager to be
instantiated with a different start and end marker when calling the
validation functions.

Addresses Issue: https://github.com/rackerlabs/deuce-valere/issues/10
FYI - I usually have done this in setUp() since most tests will use the information in one form or another. So if you are going to add more extensive tests, then you may want to move it. Otherwise it's good here.