Add a forecast module (#180)

* cloned origin/master

* removed siphon files

* Added files for running and testing siphon

* Renamed files and removed errant file

* Subclassed forecast models

* Updated forecast module: added more forecast classes.

* Added forecast module documentation.

* Updated documentation and Travis build files.

* Updated Travis build to include netcdf and siphon.

* Moved forecast_testing.py and added requirements.txt.

* updated Travis build conda requirements in /ci

* Modified forecast.py and updated testing docs.

* Updated setup.py and .travis.yml files

* Added nose tests for forecast.py

* Updated nosetests for forecast.py

* Updated .gitignore

* Created forecast_to_power.ipynb and updated forecast.py

* Updated test_forecast.py and forecast.py

* Added tests in test_forecast.py and modified forecast.py

* change model names

* fix super and test

* Updated forecast class & radiation models

* Updated forecast.py, fixes to solarposition.py, tools.py

* Fixed time zone handling of forecast.py, updated tutorials.

* Updated tutorials, radiation conversion for forecast.py

* Updated forecast.py tests

* Updated forecast, tests, and notebooks

* Updated documentation, tutorials, and forecast.py

* Updated forecast.py

* add rtd ymls

* add numpydoc to rtd conda env, remove from source

* try adding a simple plot with ipython directives

* add ipython directives to conf.py

* remove line numbers from ipython directives

* add blank line

* add imports

* remove mocks

* remove sphinxext

* add a blank line

* move ipython directive out of numpydoc

* remove plot from module

* clean up merge detritus

* add siphon to env

* remove sphinx_rtd_theme from our source

* add siphon to ci ymls

* Fixed test_temp_convert()

* Added exception for HTTPError

* Added HTTPError exception

* Updated HTTPError exception

* Updated HTTPError exception

* Modified test_data_query

* Reverted test_data_query modification

* add siphon to appveyor.yml

* fix tab problem

* add requires_siphon

* remove siphon from min and 3.5 ci files

* revert to pvlib/master setup.py. rm fx README and req

* remove forecast module import from init

* protect test_forecast imports with has_siphon

* reorganize tutorials

* editing forecast docs

* fx documentation should work with ipython example

* remove fx model timerange in favor of start, end

* add irrad plot

* add model description and pv power

* edit docs

* pep8 stuff

* refactor calc_radiation, add repr, add test generator

* do not import forecasting

* add a few resolutions, update notebooks

* more clean up and pep8

* deleted unused images. now auto generated as appropriate

* clean up gitattributes

* use conda-forge channel instead of unidata

* add conda forge to appveyor

* create v0.4.0 whatsnew

* update forecast module for 0.3 changes

* fix appveyor config file

* clean up merge

* notes on geographic location. clean up

* refactor forecast.py to be more explicit

* update fx tutorials. minor doc fix

* more doc edits

* add comments

* add newline

* remove http from channel

* use a big tracker for forecast example

* fix import problem

* update model descriptions

* rename temperature to temp_air

* fix bad merge in whatsnew

* fix ci env files

* fix keyword problem

* refactor transmittance. needs more

* refactoring cloud cover to irrad. not working

* add cloud cover to irradiance via cs scaling. move forecast to pytest

* update test_irradiance

* add pytestmark to test_forecast

* fix cloud_cover_to_irradiance_liujordan bugs. improve tests

* update docs

* fix appveyor build, add warnings

* clean up bad merge

* no siphon

* no conda-forge

* add comment

* add references to larson et al

* typo

* add note about difficult builds on rtd

* fix bad merge in irradiance

* update doc index

* update notebooks

* minor edit

appveyor.yml

@@ -27,7 +27,7 @@ install:
     - cmd: conda info -a
 
     # install depenencies
-    - cmd: conda create -n test_env --yes --quiet python=%PYTHON_VERSION% pip numpy scipy pandas nose pytest pytz ephem numba
+    - cmd: conda create -n test_env --yes --quiet python=%PYTHON_VERSION% pip numpy scipy pandas nose pytest pytz ephem numba siphon -c conda-forge
     - cmd: activate test_env
     - cmd: python --version
     - cmd: conda list

ci/requirements-py27.yml

@@ -1,4 +1,7 @@
 name: test_env
+channels:
+    - defaults
+    - http://conda.anaconda.org/conda-forge
 dependencies:
     - python=2.7
     - numpy
@@ -7,6 +10,7 @@ dependencies:
     - pytz
     - ephem
     - numba
+    - siphon
     - pytest
     - pytest-cov
     - nose

ci/requirements-py34.yml

@@ -1,4 +1,7 @@
 name: test_env
+channels:
+    - defaults
+    - conda-forge
 dependencies:
     - python=3.4
     - numpy
@@ -7,6 +10,7 @@ dependencies:
     - pytz
     - ephem
     - numba
+    - siphon
     - pytest
     - pytest-cov
     - nose

ci/requirements-py35.yml

@@ -1,4 +1,7 @@
 name: test_env
+channels:
+    - defaults
+    - conda-forge
 dependencies:
     - python=3.5
     - numpy
@@ -7,6 +10,7 @@ dependencies:
     - pytz
     - ephem
     - numba
+    - siphon
     - pytest
     - pytest-cov
     - nose

docs/environment.yml

@@ -1,4 +1,7 @@
 name: pvlibdocs
+channels:
+    - defaults
+#    - conda-forge  # needed for siphon, but causes path too short problems on rtd
 dependencies:
     - python=2.7
     - mock  # needed for local python 2.7 builds
@@ -13,6 +16,7 @@ dependencies:
     - numpydoc
     - matplotlib
     - seaborn
+#    - siphon
     - sphinx=1.3.5  # same versions as rtd
     - sphinx_rtd_theme=0.1.7
     - docutils=0.12