Regenerate gemspec for version 2.4.2
Regenerate gemspec for version 2.4.2

mezza/rubyXL,99cm/rubyXL,weshatheleopard/rubyXL,ThijsWouters/rubyXL,99cm/rubyXL,mezza/rubyXL,parallel588/rubyXL,ryanmark/rubyXL,ryanmark/rubyXL,weshatheleopard/rubyXL,parallel588/rubyXL,ThijsWouters/rubyXL,ryanmark/rubyXL,99cm/rubyXL,parallel588/rubyXL,weshatheleopard/rubyXL,mezza/rubyXL