add paginate_array example to readme
Add specs
Grape 0.9.0 changed how to raise a validation exception.
Merge pull request #15 from phallstrom/specs

Add specs
Merge pull request #16 from phallstrom/specs_for_grape_0.9.0

Grape 0.9.0 changed how to raise a validation exception.
Update README.md
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Merge pull request #14 from phallstrom/paginate_array_readme_example

add paginate_array example to readme