arrow

ARROW-825: [Python] Rename pyarrow.from_pylist to pyarrow.array, test on tuples

The idea is to make this function more semantically analogous to `numpy.array` -- convert to native data structure with optional explicit type.

Author: Wes McKinney <wes.mckinney@twosigma.com>

Closes #552 from wesm/ARROW-825 and squashes the following commits:

5d69c70 [Wes McKinney] Update test_jemalloc after ARROW-830
c25fdee [Wes McKinney] Update docstring
3a284b7 [Wes McKinney] Rename pyarrow.from_pylist to pyarrow.array, test on tuples