chore: Enable tag based deploy pipeline

[nmarley]

This does several things:

• Install dependencies via npm ci
• Add check-package scripts to ensure same values for both name and version in package.json and package-lock.json
• Set Travis config to only deploy on tags, and only for this repo (not forks, for example)
• Update deploy script to check tags. The first check $PACKAGE_TAG" != "$TRAVIS_TAG" makes sure the tag version number pushed via git is equal to the version number in package.json. It should be "v1.2.3" for example, for the tag, and "1.2.3" in the package.json version.

It also checks if the string "dev" exists in the tag in order to not use "latest" for a dev tag. Then it publishes the module to npm with a tag of either latest or dev.

[nmarley]

Please don't merge this as yet, I want to rebase this once #17 is merged. This should not go into that PR.

[nmarley]

Rebased onto latest master after #17 was merged.