update: added map.points function

[ayushanand18]

Overview

This PR aims to implement a maps.points() function to plot world maps with DwC data easily.

Addresses #12

Changes Introduced

• A pydwcviz.map module containing different types of maps
  • maps.points() function to generate point map from a dataframe containing occurrence records with at least decimalLongitude and decimalLatitude columns, using geopandas.

Usage

from pydwcviz import map
from pyobis import occurrences
import matplotlib.pyplot as plt

ax = map.points(occurrences.search(scientificname="Mola mola", size=100).execute())
plt.show() # required only in a non-Jupyter interface

Thanks!