Refactored tests; minor validation fixes

This release provides improved validation (a set of minor fixes enabling the octue-sdk-python 0.1.4 release) as well as a major refactor of tests for improved speed and clarity (the refactor also serving to welcome our new contributor @cortadocodes into the world of twined).

Moved Travis to Github Actions CI/CD

Because we ran out of free credit on Travis!

Updated twine structure and comprehensive validation

Major upgrade and improvements to documentation and twine structure.

Documentation was updated to allow for a slightly clearer twine structure (improved key names and a reconciled approach to treatment of files/values for inputs/configuration).

Comprehensive validation of credentials, children and manifests was added, as well as various helper methods and properties based on need in the octue-sdk-python library (which has a number of thorough use cases for the Twine class.

Examples were also added, for use as demonstrators in a development project.

Improved test coverage and exception handling

Merge pull request #36 from octue/release/0.0.12

Release/0.0.12a1

Alpha release of version 0.0.12

Major upgrade and improvements to documentation have been made. Whilst doing so, the documentation was updated to allow for a slightly clearer twine structure (improved key names and a reconciled approach to treatment of files/values for inputs/configuration).

Neither twined nor the dependent octue-sdk library are up to date with these proposed changes yet, this alpha release allows review of the latest documentation and thinking about the twine spec.

Examples were also added, for use as demonstrators in a development project.

Added pypi badge

Minor release just to add a pypi badge so users can navigate to the installable repo from GitHub.

Added credentials, children and manifest validation

Basic validation now undertaken for all strands:

• Added credential parser and checker
• Added children parser and checker
• Added manifests parser and checker (very basic)

Updated schema for manifests:

• kind now enumerated with the only option that currently makes sense, and default provided to remove the pain

Improved error logging:

• validation errors now contain a printout of what the error is. Helpful!

Added validation of schema based strands

New features:

• Added validation for schema-based strands (significant WIP against #7 and #11)
• Added unit tests to close #6 - coverage now at 100%

Improvements:

• Refactored twine validation to use the same internal methods as data validation (reduced, more elegant code)
• Implemented automatic code style application on pre-commit hook

Documentation:

• Added developer installation guide to the README
• Added release process guide reminder to the README

Improved package manifest

Fixed:

• Needed to specify include_package_data in setup.py in order to actually use the manifest.in file

Devops:

• Removed docs folders from the package - there's no point making the deployed package so large.

FIx to schema manifesting

Fixed the manifest file so deployed package includes the *schema.json files.
Added first iteration of schema files for validating submitted children and manifest entries.