MAINT: Fixed E501 Line too long error

When attempting to push changes to GitHub, tests
 returned a "757:89: E501 Line too long (90 > 88)"
 error. Line 757 was shortened in this update.

Author: Eugenia-Mazur

numpy_financial/_financial.py

@@ -754,7 +754,8 @@ def irr(values, *, raise_exceptions=False, selection_logic=_irr_default_selectio
     selection_logic: function, optional
         Function for selection logic when more than 1 real solutions is found. User may 
         insert their own customised function for selection of IRR values. 
-        The function should accept a one-dimensional array of numbers and return a number.
+        The function should accept a one-dimensional array of numbers
+        and return a number.
         
 
     Returns