fixes #92 TypeLoadException: Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute'
fixes #92 TypeLoadException: Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute'

sean-gilliam/quartznet,quartznet/quartznet,quartznet/quartznet,AlonAmsalem/quartznet,andyshao/quartznet,huoxudong125/quartznet,quartznet/quartznet,zhangjunhao/quartznet,neuronesb/quartznet,quartznet/quartznet,sean-gilliam/quartznet,sean-gilliam/quartznet,xlgwr/quartznet,sean-gilliam/quartznet,quartznet/quartznet,sean-gilliam/quartznet,AndreGleichner/quartznet,RafalSladek/quartznet