Merge pull request #1 from mrjbq7/master

Update
 * Bug-fix: MAVP's 'periods' input array not accepted by Function.set_input_arrays
only require necessary keys to be provided in input_arrays. this fixes issue #38
fix abstract test for new set_input_arrays behavior
add test cases for new input_arrays behavior
add tests for MAVP
update cythoned abstract.c file
Merge pull request #39 from briancappello/master

merge aaiyers MAVP fix, improve setting input_arrays and add tests