Major version bump; accepting breaking changes into dev

Author: nblumhardt

src/Serilog.Sinks.File/Serilog.Sinks.File.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <Description>Write Serilog events to text files in plain or JSON format.</Description>
-    <VersionPrefix>4.1.0</VersionPrefix>
+    <VersionPrefix>5.0.0</VersionPrefix>
     <Authors>Serilog Contributors</Authors>
     <TargetFrameworks>net45;netstandard1.3;netstandard2.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>