Add reference to ExpectedException. Fixes #806.

The ExpectedException can be used for better exception testing. The
reference should guide the reader to its documentation.
Mention required modifiers of @Parameters method. Fixes #809.
Merge pull request #810 from stefanbirkner/parameterized-docs

Mention required modifiers of @Parameters method. Fixes #809.
Merge pull request #808 from stefanbirkner/exception-testing

Add reference to ExpectedException. Fixes #806.