[Python/C++] Decimal test failure on MSVC

[asfimport]

This is the last remaining item to enable running the pyarrow test suite locally. Appveyor issues may have to wait until post 0.3 so they can be further diagnosed.

Reporter: Wes McKinney / @wesm
Assignee: Phillip Cloud / @cpcloud

Related issues:

• Arrow 0.3 release (blocks)

_{Note: This issue was originally created as ARROW-885. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Duplicate of ARROW-914