DevTest 10.1, lib/shared/poi-3.14.jar contains the org.apache.poi.ss.usermodel.Cell class you are using.
DevTest 10.3, lib/shared/poi-3.17.jar also contains the class.
The problem is that in poi-3.14.jar used in DT 10.1, the Cell class does not have a getCellTypeEnum method.
In poi-3.17.jar (deployed with DT 10.3), the Cell class has the getCellTypeEnum method; however, it appears this method is scheduled for removal -- see below.
@Removal(version="4.2")
public abstract CellType getCellTypeEnum();
I don't see the CellType class in 3.14, and it also looks as if the CellType class in 3.17 is being deprecated.
Perhaps another approach is viable from a long term perspective, or perhaps, it is possible set up your own enum and use 3.14's getCellType and examine the int value returned.
None = -1, Numeric = 0, String = 1, Formula = 2, Blank = 3, Boolean = 4, Error = 5