Fixes node14 Dockerfile to reference the correct Node.js Docker image version

[ggrussenmeyer]

Signed-off-by: Guillaume Grussenmeyer ggrussenmeyer@protonmail.com

Description

Update node Docker image version to 14-alpine in node14/Dockerfile (was 12-alpine).

Motivation and Context

• I have raised an issue to propose this change (required)

Which issue(s) this PR fixes

Fixes #253

How Has This Been Tested?

By verifying the output of docker run node14-ci node --version.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Version change (see: Impact to existing users)

Impact to existing users

Users that thought they were running Node.js v14 when using the node14 template were actually running v12.
After this PR they'll be actually running v14.
I'm unable to evaluate the effective impact; YMMV.

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[alexellis]

LGTM