BUG/TST: should skip openpyxl before testing version compat

Author: cpcloud

pandas/io/tests/test_excel.py

@@ -1217,9 +1217,9 @@ def test_ExcelWriter_dispatch(self):
             import xlsxwriter
             writer_klass = _XlsxWriter
         except ImportError:
+            _skip_if_no_openpyxl()
             if not openpyxl_compat.is_compat():
                 raise nose.SkipTest('incompatible openpyxl version')
-            _skip_if_no_openpyxl()
             writer_klass = _OpenpyxlWriter
 
         with ensure_clean('.xlsx') as path: