Simple algorithms unit test case

Useful for making sure pandas, numpy, and scipy are installed correctly.  Must be run from a directory such that `settings` is in the path.

For example:

    python tests/algorithms_test.py

Works with [nose](https://github.com/nose-devs/nose) (optional):

    nosetests -v --nocapture

Results, with coverage:

```
$ nosetests -v --nocapture --with-coverage --cover-package=algorithms analyzer
test_first_hour_average (algorithms_test.TestAlgorithms) ... ok
test_grubbs (algorithms_test.TestAlgorithms) ... ok
test_histogram_bins (algorithms_test.TestAlgorithms) ... ok
test_least_squares (algorithms_test.TestAlgorithms) ... ok
test_mean_subtraction_cumulation (algorithms_test.TestAlgorithms) ... ok
test_run_selected_algorithm (algorithms_test.TestAlgorithms) ... ok
Assert that a user can add their own custom algorithm. ... ok
test_simple_stddev_from_moving_average (algorithms_test.TestAlgorithms) ... ok
test_stddev_from_moving_average (algorithms_test.TestAlgorithms) ... ok
test_tail_avg (algorithms_test.TestAlgorithms) ... ok

Name         Stmts   Miss  Cover   Missing
------------------------------------------
algorithms     101      6    94%   134, 159, 188, 197-199
----------------------------------------------------------------------
Ran 10 tests in 3.173s

OK
```