workbook_validate_worksheet_name renamed to workbook_validate_sheet_name

[jarredholman]

WorkbookWrappers#validate_worksheet_name is broken because the function in libxlsxwriter was changed from workbook_validate_worksheet_name to workbook_validate_sheet_name

libxslxwriter header:

fast_excel/libxlsxwriter/include/xlsxwriter/workbook.h

Line 855 in 8fafe6f

lxw_error workbook_validate_sheet_name(lxw_workbook *workbook,

binding:

fast_excel/lib/fast_excel/binding/workbook.rb

Line 327 in 8fafe6f

attach_function :workbook_validate_worksheet_name, :workbook_validate_worksheet_name, [Workbook, :string], :error

fast_excel/lib/fast_excel/binding/workbook.rb

Lines 149 to 151 in 8fafe6f

	def validate_worksheet_name(sheetname)
	Libxlsxwriter.workbook_validate_worksheet_name(self, sheetname)
	end