CCDCesque: model end positioning can be wrong

[ceholden]

In v0.5.5 and previous versions, if timeseries monitoring in CCDCesque ended on an observation that was screened as noise in the monitoring period (using remove_noise=True), the last record's end attribute would be recorded as the date of this screened observation.

Nobody seems to have noticed before because it's only a 8-16 day offset when using Landsat data and CCDCesque models end on the last observation before the consecutive check so one more observation behind this number wasn't noticeable. I only found it when trying to validate some performance optimizations occuring within v0.6.0 (see #70).

This bug was resolved in the optimization implementations (per #70), specifically in 31e21f9