Ensure keys in configuration are always strings; fix configuration serialisation

Contents (#8)

Fixes

• Ensure keys in Configuration are always strings so its instances are directly JSON-compatible
• Convert configurations to dictionaries before using as metadata to avoid JSON serialisation error

Testing

• Fix deliberate exception raising in cloud upload tests

Avoid h5py dependency unless installing cloud functions

Summary

Only require the h5py dependency included in the octue package when installing the cloud functions. This avoids installing it where the main data-gateway code is installed, which is usually a Raspberry Pi that doesn't have the required system dependency to use HDF5 files.

Contents (#5)

Operations

• Update readme with new coverage badge

Dependencies

• Only require h5py dependency in cloud functions

Uncover error raised during cloud upload; add GitHub workflows

Contents (#1)

Fixes

• Log actual exception caught when error is raised during window upload to cloud

Operations

• Replace GitLab config, templates, and workflows with GitHub equivalients
• Add semantic version check workflow
• Add automated release notes workflow
• Run tests on Windows and MacOS (tests previously ran only on Linux)
• Upload code coverage to coverage.io

Testing

• Fix cloud functions tests to work on GitHub by providing credentials as a temporary file

Serialise sensor coordinates before passing to BigQuery

Contents

Fixes

• Serialise sensor coordinates before storing in BigQuery