fix default branch for .wiki and when using ssh (#284)

__test__/git-auth-helper.test.ts

@@ -714,6 +714,7 @@ async function setup(testName: string): Promise<void> {
     ),
     env: {},
     fetch: jest.fn(),
+    getDefaultBranch: jest.fn(),
     getWorkingDirectory: jest.fn(() => workspace),
     init: jest.fn(),
     isDetached: jest.fn(),

__test__/git-directory-helper.test.ts

@@ -408,6 +408,7 @@ async function setup(testName: string): Promise<void> {
     config: jest.fn(),
     configExists: jest.fn(),
     fetch: jest.fn(),
+    getDefaultBranch: jest.fn(),
     getWorkingDirectory: jest.fn(() => repositoryPath),
     init: jest.fn(),
     isDetached: jest.fn(),