Maintenance: update dependencies and improve get-version.sh

[samporapeli]

Now get-version.sh can handle the following situations:

• Launched outside a Git directory (in that case, version is unknown) -- this might happen when working with bare git repositories
• Launched from a Bourne shell (or similar, such as dash) -- this seems to happen on some systems when npm launches the build command

Additionally, npm audit fix was used to update the dependencies.