deprecated append method fname.append

[salme146]

I just wanted to share that when I run this code:

Battery_water_levels = Battery.get_data( product='hourly_height', begin_date='20040601', end_date='20220831', datum="MSL", units="metric", time_zone="gmt")

I get this warning:

/Users/scook/opt/miniconda3/envs/pangeo_3.8/lib/python3.8/site-packages/noaa_coops/noaa_coops.py:551: FutureWarning: The frame.append method is deprecated and will be removed from pandas in a future version. Use pandas.concat instead. df = df.append(df_new)

[337mrichard]

Just wanted to say that at the time of this comment this is still an issue. Thanks!

[GClunies]

Addressed in #38