Revert to base appveyor build

OhmGraphite/FodyWeavers.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <Weavers>
-  <Costura ExcludeAssemblies='TargetExe|TargetExeTest' CreateTemporaryAssemblies='true' DisableCleanup='true'/>
+  <Costura />
 </Weavers>

appveyor.yml

@@ -1,8 +1 @@
-image: 'Visual Studio 2017'
-build: off
-test_script:
-  cmd: |
-      git submodule update --init --recursive
-      nuget restore
-      dotnet build ./OhmGraphite/OhmGraphite.csproj
-      dotnet test ./OhmGraphite.Test/OhmGraphite.Test.csproj
+image: 'Visual Studio 2017'