Remove bad advice on calling steps from step definitions
Merge pull request #69 from abotalov/patch-2

Remove bad advice on calling steps from step definitions
Remove invalid advice

Capybara Readme clearly says:
```
The two following statements are functionally equivalent:

page.should_not have_xpath('a')
page.should have_no_xpath('a')
```
Merge pull request #68 from abotalov/patch-1

Remove invalid advice