Expand t.Fatal(err) to include more debugging information

[minusnine]

Go style best practices dictate that test failures should be useful.

https://github.com/golang/go/wiki/CodeReviewComments#useful-test-failures

In most cases, the error message should include:

• The function that failed.
• The inputs to the function.
• The output of the function
• For at least non-error types, the expected value.

We should audit and expand the errors in remote_test.go to ensure each failure is handled. In particular, the errors like:

title, err := wd.Title()
if err != nil {
  t.Fatal(err)
}

Should be expanded like:

title, err := wd.Title()
if err != nil {
  t.Fatalf("wd.Title() returned error: %v", err)
}