Simple locator tests

@mfalesni, it seemed useful to have test coverage on this, so I put together a test module for this trying to demonstrate your proposed use-cases. There are test errors, which I will detail inline.
```
E       InvalidSelectorException: Message: u'The given selector h1#id1 is either invalid or does not result in a WebElement. The following error occurred:
InvalidSelectorError: Unable to locate an element with the xpath expression h1#id1 
because of the following error:
[Exception... "The expression is not a legal expression."  code: "12" nsresult: "0x805b0033 (SyntaxError)"
```