Prep for release 0.5.8
Prep for release 0.5.8

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