Varying first cutoff time for each target group

[jeff-hernandez]

Closes #215 by supporting columns as values for minimum_data in a label search. This functionality allows users to vary the first cutoff time for each target group. For example, with a table of customers, you can start the labeling process at the varying times that the accounts were created.

[codecov]

Codecov Report

Merging #258 (bb4b844) into main (f396057) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main      #258   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           28        28           
  Lines         1270      1304   +34     
=========================================
+ Hits          1270      1304   +34     

Impacted Files	Coverage Δ
composeml/label_maker.py	100.00% <100.00%> (ø)
composeml/tests/test_data_slice/test_extension.py	100.00% <100.00%> (ø)
composeml/tests/test_label_maker.py	100.00% <100.00%> (ø)

[rwedge]

Can you update the relevant docstring and maybe include an example in the documentation?

[jeff-hernandez]

@rwedge I updated the docstring and also added this guide in the docs

[rwedge]

Can we test a series that has a mix of date and number strings / a series that has only number strings?

[jeff-hernandez]

@rwedge I updated the test to include timedelta string and integer values. Although using a mix of date and number can technically work, that seems like an edge use case and I don't think we should test that usage.

[rwedge]

LGTM