[python] pygrib installation

pygrib is the python interface of Grib-API (ECMWF).

1. install Grib-API.
(1) Download the source for Grib-API (https://software.ecmwf.int/wiki/display/GRIB/Releases).
(2) Follow GRIB API Autotools to install Grib-API (https://software.ecmwf.int/wiki/display/GRIB/GRIB+API+Autotools+installation)
path: ~/local

2. install pygrib
(1) Originally I want to install using pip, but it failed. so I install from source
(2) Download the source for pygrib (https://pypi.python.org/pypi/pygrib)
(3) Set environmental path:
$ export GRIBAPI_DIR=/usr/local/grib_api_dir
$ export JASPER_DIR=/usr
(4) Go to the download folder:
$ tar zxvf pygrib-x.x.x.tar.gz
$ cd pygrib-x.x.x python setup.py
$ install –user
$ python test.py