Pin pandas version to 0.23 until tests support 0.24

[rwedge]

Pandas released version 0.24.0 recently. This PR contains some bugfixes to the tests to make the code more compatible with the new pandas version. The way featuretools implements the LatLong type is incompatible with 0.24 currently (see pandas issue #24986) so until that situation is resolved we're restricting featuretools to pandas 0.23. Pandas 0.24 should work excluding latlongs.

[codecov]

Codecov Report

Merging #383 into master will decrease coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #383      +/-   ##
==========================================
- Coverage   95.79%   95.75%   -0.04%     
==========================================
  Files          89       89              
  Lines        7754     7755       +1     
==========================================
- Hits         7428     7426       -2     
- Misses        326      329       +3

Impacted Files	Coverage Δ
featuretools/tests/utils_tests/test_time_utils.py	94.28% <100%> (ø)	⬆️
...computational_backends/calculate_feature_matrix.py	96.98% <100%> (+0.01%)	⬆️
...utational_backend/test_calculate_feature_matrix.py	99.3% <100%> (ø)	⬆️
...aturetools/primitives/standard/binary_transform.py	97.79% <0%> (-1.11%)	⬇️

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[kmax12]

Looks good to me!