CLN: Remove io.data and io.wb

Deprecated in 0.17.0.

xref pandas-devgh-13735.

Author: gfyoung

doc/source/whatsnew/v0.22.0.txt

@@ -136,6 +136,7 @@ Removal of prior version deprecations/changes
 - ``pd.tseries.util.pivot_annual`` has been  removed (deprecated since v0.19). Use ``pivot_table`` instead (:issue:`18370`)
 - ``pd.tseries.util.isleapyear`` has been removed (deprecated since v0.19). Use ``.is_leap_year`` property in Datetime-likes instead (:issue:`18370`)
 - ``pd.ordered_merge`` has been removed (deprecated since v0.19). Use ``pd.merge_ordered`` instead (:issue:`18459`)
+- The ``pandas.io.wb`` and ``pandas.io.data`` modules have been removed (:issue:`13735`)
 
 .. _whatsnew_0220.performance: