Dev version bump [skip ci]

Author: nblumhardt

src/Seq.Client.Log4Net/Seq.Client.Log4Net.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>net40;net462;netstandard2.0</TargetFrameworks>
-    <VersionPrefix>3.1.0</VersionPrefix>
+    <VersionPrefix>3.1.1</VersionPrefix>
     <Authors>Datalust Pty Ltd and Contributors</Authors>
     <Description>Apache log4net appender for .NET Framework and .NET Standard/Core that writes to the Seq log server over HTTP.</Description>
     <PackageIconUrl>http://datalust.co/images/nuget/seq-client-log4net.png</PackageIconUrl>