Add and fix tests

src/file/relationships/relationships.spec.ts

@@ -0,0 +1,30 @@
+// tslint:disable:no-string-literal
+import { expect } from "chai";
+
+import { Formatter } from "../../export/formatter";
+import { Relationships } from "./relationships";
+
+describe("Relationships", () => {
+    describe("#constructor()", () => {
+        it("should create section properties with options", () => {
+            const properties = new Relationships();
+            const tree = new Formatter().format(properties);
+            expect(Object.keys(tree)).to.deep.equal(["Relationships"]);
+            expect(tree["Relationships"]).to.be.an.instanceof(Array);
+            expect(tree["Relationships"][0]).to.deep.equal({
+                _attr: { xmlns: "http://schemas.openxmlformats.org/package/2006/relationships" },
+            });
+            expect(tree["Relationships"][1]).to.deep.equal({
+                Relationship: [
+                    {
+                        _attr: {
+                            Id: "rId1",
+                            Type: "http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles",
+                            Target: "styles.xml",
+                        },
+                    },
+                ],
+            });
+        });
+    });
+});