v0.15.2: Fix hash of NCube & add plotting utilities (#112)

* Bugfix: change the `__hash__` attribute of `NCubeInterior`
* Add a return value of `None` when `Domain.get_subdomain` is called with the empty tuple
* Add plotting functions in `utilities.utils.py`
* Update library version to 0.15.2

v0.15.1: Add SphericalMapping (#109)

Add 3D analytical mapping `SphericalMapping`, which represents a sphere (or a portion of it) parametrized by the spherical coordinates `(r, theta, phi)`, i.e. (radius, inclination, azimuth).

Additional commits:
  - Ignore swap files
  - Update version to 0.15.1

v0.15.0: Geometry file for multiple patches (#107)

Improve the geometry files to handle multiple patches. The following changes have been made:

- Add the mapping name in the `todict` methods
- Generalize the `Domain.from_file` method to handle multiple patches
- Add `_plus` suffix to the coordinates of the mapping defined on the "plus side" of an interface
- Remove the targets from the interior domain
- Update the SymPDE version

v0.14.1: Run tests on installed library (#104)

Make sure that the installed version of SymPDE, either editable or not, passes the unit tests:

- Add `__init__.py` to all `tests` subdirectories, which are then installed as part of the package.
- Run tests with command `pytest --pyargs sympde`.
- Run tests from the home directory, instead of the cloned repository, to make sure that the installed tests are run.

Further, add `__init__.py` to `sympde.utilities`, the lack of which made every instance of non editable installs of SymPDE fail.

Co-authored-by: Yaman Güçlü <yaman.guclu@gmail.com>

v0.14.0: Replace `lambdify` function with `lambdify_sympde` (#103)

Add a new function `lambdify_sympde` as an improvement over Sympy's `lambdify`. Previous uses of `lambdify` are replaced by `lambdify_sympde`, which correctly handles Numpy arrays broadcasting rules. Further, add array tests to `test_callable_mapping.py`.

v0.13.1: Fix callable mapping (#102)

* Fix bug in ldim/pdim properties of CallableMapping
* Add unit tests for CallableMapping class
* Update version to 0.13.1
* Make Codacy happy

v0.13.0: Replace OrderedDict with dict. Remove yamlloader dependency (#101)

As of Python 3.7, `dict` objects are now insertion-ordered. For this reason, we can replace all `OrderedDict` objects with standard `dict`s. Consequently, support for Python 3.6 and lower is stopped and the `yamlloader` package is not needed anymore.

Co-authored-by: Yaman Güçlü <yaman.guclu@gmail.com>

v0.12.0: FEEC multipatch (#95)

- Improve multiple patches objects to handle vector-valued functions
- Add corners computation for 2D geometries
- Split interfaces first before evaluation in TerminalExpr
- Change `TerminalExpr` signature, now takes `(expr, domain)` as positional arguments
- Change `LogicalExpr` signature, now takes `(expr, domain)` as positional arguments
- Update library version

NOTE: With the new signatures of `TerminalExpr` and `LogicalExpr` the user can define his/her own coordinates, but this is beyond the scope of this PR.

v0.11.0: Remove "Test" from names of classes {Scalar|Vector}TestFunction (#97)

* Remove 'Test' from {Scalar|Vector}TestFunction

* Update version

* Rename IndexedTestTrial as IndexedVectorFunction

* Escape special characters in docstring

v0.10.10: Do not split fields in TensorExpr (#94)

Differently from basis functions, fields cannot (and should not) be decomposed into a tensor-product of 1D fields.