Moving to pandas=1.1.4

[PokhodenkoSA]

There are several pandas in README.md.

[pep8speaks]

Hello @kozlov-alexey! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file sdc/datatypes/hpat_pandas_series_functions.py:

Line 781:23: E111 indentation is not a multiple of four Line 781:23: E117 over-indented

• In the file sdc/tests/test_series.py:

Line 5345:9: E124 closing bracket does not match visual indentation

[kozlov-alexey]

Closing as changes will be made in a different PR (from branch of the PR needs changing).