tests: Enable previously disabled UNC tests on CI. (#4575)

Windows CI had a bug which has been fixed, re-enable
those commented tests.

appveyor.yml

@@ -24,6 +24,8 @@ install:
 # To run your custom scripts instead of automatic MSBuild
 build_script:
   # Compile
+  # We need to disable firewall - https://github.com/appveyor/ci/issues/1579#issuecomment-309830648
+  - ps: Disable-NetFirewallRule -DisplayName 'File and Printer Sharing (SMB-Out)'
   - appveyor AddCompilationMessage "Starting Compile"
   - cd c:\gopath\src\github.com\minio\minio
   - go run buildscripts/gen-ldflags.go > temp.txt

pkg/x/os/stat_windows_test.go

@@ -71,9 +71,6 @@ func sameFile(fi1, fi2 os1.FileInfo) bool {
 }
 
 func TestNetworkSymbolicLink(t *testing.T) {
-	// Skipping this test for now - appveyor builds are failing.
-	t.Skip()
-
 	dir, err := ioutil.TempDir("", "TestNetworkSymbolicLink")
 	if err != nil {
 		t.Fatal(err)