Numpoly

==========================

CHANGED:
* Small documentation update.

==========================

ADDED:
* Support for alpha, beta, rc, dev, post releases.
* Validate tags against install version.
* Polynomial function: `decompose`.

===========================

CHANGED:
* Change string representation to display polynomial
by insertion order (affecting a lot of examples).

===========================

ADDED:
* Global constants added for manipulating string representation.

CHANGED:
* `monomial`: reorder args such that `indeterminants` argument is at the end.

===========================

ADDED:
* Include Sphinx docs in CircleCI testing.
* Add Construct chapter to Sphinx.
* Numpy function additions: `repeat`.

CHANGED:
* Rename `toarray -> tonumpy`, `as_ndarray -> values` (function -> property).

===========================

ADDED:
* Documentation update:
* Introduction to `ndpoly` baseclass added.
* Polynomial function collection.
* Enforce complete function list through `sphinx_automodapi`.
* Read-the-docs deployment configuration.
* `ndpoly` method: `as_ndarray`.
* Numpy function: `stack`.

CHANGED:
* Remove functions mappings between exponents and keys in favor of in-line
solution.

FIXED:
* Bugfixes and code cleanups for `concatenate`, `*stack` and multiplications.