Update pandas to 1.4.1 (#667)

* Only update for Python >= 3.7

Author: pyup-bot

extra_requirements.txt

@@ -15,7 +15,7 @@ scandir>=1.8
 # we use the latest version to see any problems with new versions
 pandas==1.1.5; python_version <= '3.6'
 pandas==1.3.5; python_version == '3.7'
-pandas==1.4.0; python_version > '3.7'
+pandas==1.4.1; python_version > '3.7'
 xlrd==1.2.0; python_version <= '3.6'
 xlrd==2.0.1; python_version > '3.6'
 openpyxl==3.0.9