Fix for numeric data interpreted as strings.
Fix for numeric data interpreted as strings.

liukaijv/XlsxWriter,gechong/XlsxWriter,jkyeung/XlsxWriter,Thhhza/XlsxWriter,yaojingwu1992/XlsxWriter,yaojingwu1992/XlsxWriter,jmcnamara/XlsxWriter,jmcnamara/XlsxWriter,jvrsantacruz/XlsxWriter,jkyeung/XlsxWriter,applicationdevm/XlsxWriter,Thhhza/XlsxWriter,applicationdevm/XlsxWriter,seize-the-dave/XlsxWriter,jkyeung/XlsxWriter,gechong/XlsxWriter,mdeemer/XlsxWriter,applicationdevm/XlsxWriter,liukaijv/XlsxWriter,seize-the-dave/XlsxWriter,jkyeung/XlsxWriter,jvrsantacruz/XlsxWriter,jvrsantacruz/XlsxWriter,jvrsantacruz/XlsxWriter,mdeemer/XlsxWriter,jmcnamara/XlsxWriter,yaojingwu1992/XlsxWriter,Thhhza/XlsxWriter,Thhhza/XlsxWriter,applicationdevm/XlsxWriter,liukaijv/XlsxWriter,mdeemer/XlsxWriter,yaojingwu1992/XlsxWriter,gechong/XlsxWriter,seize-the-dave/XlsxWriter,seize-the-dave/XlsxWriter,jmcnamara/XlsxWriter,mdeemer/XlsxWriter,gechong/XlsxWriter,liukaijv/XlsxWriter