Add support for Swift 3.0

Tests/StencilTests/TemplateSpec.swift

@@ -0,0 +1,14 @@
+import Spectre
+import Stencil
+
+
+func testTemplate() {
+  describe("Template") {
+    $0.it("can render a template from a string") {
+      let context = Context(dictionary: [ "name": "Kyle" ])
+      let template = Template(templateString: "Hello World")
+      let result = try template.render(context)
+      try expect(result) == "Hello World"
+    }
+  }
+}