grib2io release 0.2.0

This is the first release of grib2io. Version 0.2.0 is also available on PyPI. As of this release grib2io can perform the following major functions:

• Read a file containing GRIB2 Messages. If a GRIB2 Message contains sub messages, grib2io will "flatten" into multiple GRIB2 Messages.
• When read, the GRIB2 file will "indexed". This is not the same as a GRIB2 Index file. The indexing keeps track of the location of a GRIB2 Message in the file and catalogs most GRIB2 metadata for filtering/parsing (to be implemented in a future release) and allows for reading of GRIB2 Messages in a random-access manner.
• Unpack GRIB2 data
• Where possible, GRIB2 integer code values are translated into descriptive text via NCEP GRIB2 tables.

IMPORTANT: At this time, grib2io cannot create a new GRIB2 Message nor can it write to a new file (to be implemented in a future release).