Cleaner python3 example for use with gzip #14

Not much of an 'issue', but...
The usage example with gzip could be better.

import ish_parser
import gzip

ish_filename = 'path/to/a/ish/file.gz'

# Read content
parser = ish_parser.ish_parser()
with gzip.open(ish_filename, 'rb') as gzstream:
    for line in gzstream:
        ishp.loads(line.decode('utf-8'))

# get the list of all reports
reports = parser.get_reports()
print(len(reports))

I'm currently working on code to fetch the data for a particular station over a particular range.
Also converting some results (just air_temperature for now) into pandas dataframes.
If your interested, I can submit that code to you if it ever gets done to a 'clean enough' standard.

Oh, and thanks for writing a parser for the insane mess... I was not looking forward to that.