Issue421 durack1 add seawater packages

[durack1]

@doutriaux1 take a look at this in response to #421

[durack1]

@doutriaux1, yep also seems like we've got these in the build queue too:
[INFO] These are the packages that we will try to build: basemap;CDAT;CURL;Cython;FFMPEG;g2clib;gdal;GEOS;**gsw**;gui_support;h5py;HDF5;ZMQ;pyzmq;tornado;IPYTHON;jasper;jpeg;LAPACK;lepl;libcf;Matplotlib;SIX;DATEUTILS;PYPARSING;Mpi4py;PYOPENSSL;setuptools;MyProxyClient;NetCDF;NetCDFPLUS;Numexpr;NUMPY;MPI;OSMesa;Python;**seawater**;VTK;pkgconfig;png;pyspharm;PyTables;readline;R;scikits;SCIPY;pip;Shapely;pygments;markupsafe;jinja2;docutils;Sphinx;freetype;zlib;libXML2;libXSLT;png;pixman;fontconfig;tiff;Curses;CMOR;udunits2;uuid;UVCMETRICS;vistrails;YASM;PYLIBXML2;CDATLogger;pyclimate;scientificpython;windspharm;eof2;eofs;windfield

[doutriaux1]

@durack1 you need to make them dependent on python at least

[durack1]

@doutriaux1 isn't that achieved in the gsw/seawater_deps.cmake files set(gsw ${gsw_pkg} ${python_pkg})

[durack1]

@doutriaux1 ok these both need numpy
gsw: https://github.com/ocefpaf/python-gsw/blob/master/setup.py#L81-82
seawater: https://github.com/ocefpaf/python-seawater/blob/master/setup.py#L60-61

[durack1]

@doutriaux1 ok this one should be good to go - I fixed the dependencies

[aashish24]

This won't work. SEAWATER_VERSION is not set globally or in parent scope.

[aashish24]

@durack1 please see my comment above. This branch needs some fix.

[durack1]

@aashish24 yep thanks for that, it should now be fixed..

[aashish24]

thanks. LGTM 👍