CLIMATE-404, Open Climate Workbench Command Line tool

This is command line tool that uses OCW API
and lets user to upload a local model file, pick
an observation to run metrics and get resutls as plots.
Right now it just accepts one model and one observation
and can run Bias as metric.
Minor typo fix in README
Merge branch 'CLIMATE-403', Resolved CLIMATE-404, Merge PR #82.
CLIMATE-241 - Update draw_taylor_diagram docstring format
CLIMATE-241 - Update draw_subregions docstring format
CLIMATE-241 - Update draw_time_series docstring format
CLIMATE-241 - Update draw_contour_map docstring format
CLIMATE-241 - Update draw_portrait_diagram docstring format
Resolve CLIMATE-241. Merge PR #83.
CLIMATE-482 - Add basic StdDevRatio metric

- Add a version of StdDevRatio without an yearly/seasonal rebinning
  prior to metric calculation.
CLIMATE-483 - Add basic PatternCorrelation metric

- Rename old PatternCorrelation metric to TemporalPatternCorrelation
  since it does an annual reshaping of the datasets before doing a
  comparison and that isn't adequately reflected in the metric's name.
  The new name also falls in line with the functionality of the
  TemporalStdDevRatio metric which also does such a rebin.
- Add basic PatternCorrelation metric that uses
  scipy.stats.pearsonr to return the r_value for the reference
  and target datasets. Note, the metric no longer returns a tuple of
  values. It now only returns the r_value. This falls much more in line
  with the metrics name in my opinion.
CLIMATE-483 - Update PatternCorrelation tests
Resolve CLIMATE-482. Merge PR #84.
Resolve CLIMATE-483. Merge PR #85.
CLIMATE-484 - Remove rebinning metrics

- Drop SpatialStdDevRation, TemporalPatternCorrelation,
  SeasonalSpatialStdDevRation, and SeasonalPatternCorrelation.
CLIMATE-484 - Remove rebinning metrics from tests
CLIMATE-484 - Remove rebinning metrics from examples.
Resolve CLIMATE-484. Merge PR #86.
CLIMATE-489 - Add better subset error reporting

- Bounds checking now builds a list of errors and reports all offending
  bounds values in a single ValueError.
- Update subset docstring to reflect change in return value. Only True
  is returned when the subset is valid, otherwise a ValueError is
  raised.
Resolve CLIMATE-489. Merge PR #87.