Refactor tests

Remove 'maker' parameter from container 'iospec' tests.
ListOf tests

Add tests to confirm that ListOf initializes correctly with all
different nested containers. These tests are being added becuase of a
bug discovered when 'iomanager' was being used in the
'pyramid_apitree' distribution.
Fix ListOf

Fix: ListOf instantiates with all nested container types.
'Input', 'Output' error tests

Add tests to confirm that 'InputVerificationError' is raised when
'verify_input' is called, and 'OutputVerificationError' is raised when
'verify_output' is called.
'Input...', 'Output...' errors

Implement 'InputVerificationFailureError' and
'OutputVerificationFailureError'.
Coercion function parameters

All coercion functions now must accept two parameters: 'value' and
'expected_type'. This change allows for coercion functions to be
re-usable; a single coercion function can be applied to more than one
type.
Merge branch 'dev/verification-errors' into develop
Prepare release 0.3.2

Update version number.

Update changelog.
Merge branch 'release-0.3.2'