Fix tseries.offsets docstrings with missing period in the summary (set 3)

[bhuvanakundumani]

Same as #132 but for the next docstrings:
pandas.tseries.offsets.Day.normalize: Summary does not end with a period
pandas.tseries.offsets.Hour.normalize: Summary does not end with a period
pandas.tseries.offsets.Minute.normalize: Summary does not end with a period
pandas.tseries.offsets.Second.normalize: Summary does not end with a period
pandas.tseries.offsets.Milli.normalize: Summary does not end with a period
pandas.tseries.offsets.Micro.normalize: Summary does not end with a period
pandas.tseries.offsets.Nano.normalize: Summary does not end with a period
pandas.tseries.offsets.BDay.normalize: Summary does not end with a period
pandas.tseries.offsets.BMonthEnd.normalize: Summary does not end with a period
pandas.tseries.offsets.BMonthBegin.normalize: Summary does not end with a period
pandas.tseries.offsets.CBMonthEnd.normalize: Summary does not end with a period
pandas.tseries.offsets.CBMonthBegin.normalize: Summary does not end with a period
pandas.tseries.offsets.CDay.normalize: Summary does not end with a period
pandas.tseries.frequencies.to_offset: Summary does not end with a period