Add new row synthesis single table metric

[katxiao]

Resolves #207

[pvk-developer]

Minor, but not sure what columns can be:
You can always cast to list and this will be one dimensional:

In [1]: columns_list = ['a', 'b', 'c']
In [2]: columns_set = {'a', 'b', 'c'}
In [3]: columns_tuple = ('a', 'b', 'c')

In [4]: list(columns_list)
Out[4]: ['a', 'b', 'c']

In [5]: list(columns_set)
Out[5]: ['b', 'c', 'a']

In [6]: list(columns_tuple)
Out[6]: ['a', 'b', 'c']

If columns can be a str then don't do this as it will split it in letters

[katxiao]

It should always be a list or a set.

[codecov-commenter]

Codecov Report

Base: 70.18% // Head: 73.60% // Increases project coverage by +3.41% 🎉

Coverage data is based on head (b17f299) compared to base (62e6b73).
Patch coverage: 100.00% of modified lines in pull request are covered.

❗ Current head b17f299 differs from pull request most recent head f5d43c0. Consider uploading reports for the commit f5d43c0 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #226      +/-   ##
==========================================
+ Coverage   70.18%   73.60%   +3.41%     
==========================================
  Files          70       72       +2     
  Lines        2482     2811     +329     
==========================================
+ Hits         1742     2069     +327     
- Misses        740      742       +2     

Impacted Files	Coverage Δ
sdmetrics/multi_table/__init__.py	100.00% <ø> (ø)
sdmetrics/multi_table/multi_single_table.py	82.71% <100.00%> (+0.89%)	⬆️
sdmetrics/reports/single_table/plot_utils.py	100.00% <100.00%> (ø)
sdmetrics/single_column/__init__.py	100.00% <100.00%> (ø)
sdmetrics/single_column/statistical/__init__.py	100.00% <100.00%> (ø)
...etrics/single_column/statistical/range_coverage.py	100.00% <100.00%> (ø)
sdmetrics/single_table/__init__.py	100.00% <100.00%> (ø)
sdmetrics/single_table/multi_single_column.py	90.62% <100.00%> (+0.46%)	⬆️
sdmetrics/single_table/new_row_synthesis.py	100.00% <100.00%> (ø)
... and 4 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[pvk-developer]

This looks good now!