Update copyright to 2018.

Author: bgrainger

src/MySqlConnector/MySqlConnector.csproj

@@ -4,7 +4,7 @@
     <TargetFrameworks>net45;net46;netstandard1.3;netstandard2.0</TargetFrameworks>
     <Title>Async MySQL ADO.NET Connector</Title>
     <Description>A truly async MySQL ADO.NET provider, supporting MySQL Server, MariaDB, Percona Server, Amazon Aurora, Azure Database for MySQL and more.</Description>
-    <Copyright>Copyright 2016–2017 Bradley Grainger</Copyright>
+    <Copyright>Copyright 2016–2018 Bradley Grainger</Copyright>
     <Authors>Bradley Grainger;Caleb Lloyd</Authors>
     <AssemblyName>MySqlConnector</AssemblyName>
     <PackageId>MySqlConnector</PackageId>