This will give the developer the choice of how
they want their loop user to work.

Improve language auto discovery

Closes beat.editor#232

See merge request !53

Currently the auto discovery of the language doesn't take
into account usual errors related to loading a json file.
This patch adds more failure handling that should cover
these.

[doc] fixed external and internal links

See merge request !52

Handle duplicate key

Closes #25

See merge request !51

This hook will be used when loading JSON data to ensure
that if a key is duplicated, the system will error.

If not passing a dictionary then raise an error.

Fixing:
- Wrong schema version
- Empty optional fields
- Wrong value type

Add *.rst to list of files to include from test prefix

See merge request !50

Add dummy documentation to assets in prefix

See merge request !49

This will allow to do more tests in for example

beat/beat.editor>

Assert cleanup

Closes #24

See merge request !48

Use nose.tools assert everywhere

Create a base class for Storage and CodeStorage

Closes #23

See merge request !47

They share some logic and use so avoid code duplication and
hidden missing pieces.

Fixes #23

Improve asset information

See merge request !46

This will centralize the information and avoid duplicating
strings everywhere when one needs data from one of the various
assets.

Clean up test metadata for schema updates

Closes #22

See merge request !45