Suppress single class per file rule for test project (#2516)

Author: bahusoid

src/NHibernate.Test/Settings.StyleCop

@@ -0,0 +1,14 @@
+<StyleCopSettings Version="105">
+  <Analyzers>
+    <Analyzer AnalyzerId="StyleCop.CSharp.MaintainabilityRules">
+      <Rules>
+        <Rule Name="FileMayOnlyContainASingleClass">
+          <RuleSettings>
+            <BooleanProperty Name="Enabled">False</BooleanProperty>
+          </RuleSettings>
+        </Rule>
+      </Rules>
+      <AnalyzerSettings />
+    </Analyzer>
+  </Analyzers>
+</StyleCopSettings>