message: Fix test --example docs.
  As part of I forgot to update the help text.
  Closes
diff: @@ -21,8 +21,8 @@ pub fn cli() -> App {
  "Test only this package's library",
  "Test only the specified binary",
  "Test all binaries",
  - "Check that the specified examples compile",
  - "Check that all examples compile",
  + "Test only the specified example",
  + "Test all examples",
  "Test only the specified test target",
  "Test all tests",
  "Test only the specified bench target",
  