atbash-cipher: add generator

Author: ErikSchierboom

exercises/practice/atbash-cipher/.meta/Generator.tpl

@@ -0,0 +1,12 @@
+using Xunit;
+
+public class AtbashCipherTests
+{
+    {{for test in tests}}
+    [Fact{{if !for.first}}(Skip = "Remove this Skip property to run this test"){{end}}]
+    public void {{test.shortMethodName}}()
+    {
+        Assert.Equal({{test.expected | string.literal}}, AtbashCipher.{{test.property | string.capitalize}}({{test.input.phrase | string.literal}}));
+    }
+    {{end}}
+}