move from Travis to Github Actions

[mbjones]

Travis build minutes for open source projects are no longer adequate for our project. We decided to move to Github Actions for our CI build.

• [x] Design and test new GHA build on the preview branch
• [x] Disable the travis build by removing the .travis.yaml file
• [x] Enable the GHA build on the main branch

[mbjones]

Created a new GHA to support his that enables us to use rsync to copy files to a host. See https://github.com/DataONEorg/rsync-deploy.

[mbjones]

Site is building on preview and main. Workflow file is in https://github.com/DataONEorg/dataone-web/blob/main/.github/workflows/deploy-hugo.yaml Closing this ticket as completed.