[#291] Add tests for array/hash var scope

Accessing an item in a locally scoped array or hash variable currently fails
the "variable_scope" check in puppet-lint 1.0.0
[#291] Ignore index braces for scope variables

So that we just check the name of the variable against `variables_in_scope`.
For example `$foo` instead of `$foo[0]` or `$foo['bar']`. It won't do
anything to empty or unclosed braces.

This fixes the two tests introduced in 3ec6651 for accessing indexes of
array and hash variables. It looks like arrays were a regression introduced
in 91fd437, but hashes may not have worked previously.
Merge pull request #303 from dcarley/291-var_scope_array_hash_test

[Fixes #291] Ignore index braces for scope variables