Double quotes to single quotes (for consistency).
Add options hash so encoding may be specified.

Add an options hash to load() and keyword arguments to load_multiple.
This allows the caller to pass through options to load(), of which there
is currently one - to specify the external encoding when reading in a
file using Kernel#open().
Add tests (rspec).
Merge pull request #2 from benbasson/master

Add options hash so encoding may be specified.