Fix broken specs for Ruby 1.9.3

Commit ecd4fcf introduced a change that broke the specs for 1.9.3.

The solution was to add a `.to_a` to the call to `lines` so that an
array is always returned.

Change-Id: I880d16701d27e98161b7f075ebb66e77b45f1836
Reviewed-on: http://gerrit.causes.com/36835
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
Fix ZeroUnit linter with zero unit substrings

Fix bug where `ZeroUnit` linter would erroneously report a lint for
strings containing a substring that looked like a zero followed by
units.

The problem was we weren't excluding identifer strings from the search.

Fixes #108.

Change-Id: Id566a64231397daedc497ab3eaf905f3a00c8f8c
Reviewed-on: http://gerrit.causes.com/36834
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>