Use function naming convention in longtables

Previously, the two new functions did not use the naming convention.
This caught me in the example commit, so it will likely catch someone
who didn't write the code.
Longtable commands now use end_table_<last>_<header|footer>().

examples/longtable.py

@@ -24,17 +24,17 @@ def genenerate_longtabu():
             data_table.add_hline()
             data_table.add_row(["header 1", "header 2", "header 3"])
             data_table.add_hline()
-            data_table.end_head()
+            data_table.end_table_header()
             data_table.add_hline()
             data_table.add_row((MultiColumn(3, align='r',
                                 data='Containued on Next Page'),))
             data_table.add_hline()
-            data_table.end_foot()
+            data_table.end_table_footer()
             data_table.add_hline()
             data_table.add_row((MultiColumn(3, align='r',
                                 data='Not Containued on Next Page'),))
             data_table.add_hline()
-            data_table.end_last_foot()
+            data_table.end_table_last_footer()
             row = ["Content1", "9", "Longer String"]
             for i in range(150):
                 data_table.add_row(row)

pylatex/table.py

@@ -468,7 +468,7 @@ def end_table_header(self):
 
         self.append(Command(r'endhead'))
 
-    def end_foot(self):
+    def end_table_footer(self):
         r"""End the table foot which will appear on every page."""
 
         if self.foot:
@@ -479,7 +479,7 @@ def end_foot(self):
 
         self.append(Command('endfoot'))
 
-    def end_last_foot(self):
+    def end_table_last_footer(self):
         r"""End the table foot which will appear on the last page."""
 
         if self.lastFoot: