Pmdarima

Bug fixes:

- Out-of-sample scoring/fitting is now handled appropriately (see Issue 28).
- Fixed `TypeError` on `ARMA` predictions where `d=0` (see Issue 29).

New features:

- Created a `add_new_samples` method for `ARIMA` models so newly observed samples can be added to a model without updating its parameters. This allows future forecasts to consider the latest ground-truth samples.
- Added confidence intervals to predictions. See Issue 20

Documentation:

- Overhauled documentation with new formatting
- Migrated off of readthedocs and onto `gh-pages`

Much faster ARIMA computation since we don't compute the U or V in the SVD component.

Version 0.6.2 is a hot fix that addresses Issue 16, where Pyramid could not be installed via PIP on an EC2 Linux machine.

This release adds a hotfix to the v0.5 release, which includes the `requirements.txt` in the `MANIFEST.in` and allows pip installs from pypi.

1. Stepwise auto_arima solving (rather than merely grid search)
2. AICc ARIMA selection criterion