Provide consistent dependencies versions for lambda functions build

**Is your feature request related to a problem? Please describe.**
Because of how npm works sometimes when a lambda function is built it can update dependencies as a side effect even when the package-lock.json file is present, for automated builds like this `npm ci` should be used instead of `npm install` to provide clean and consistent dependencies versions.

**Describe the solution you'd like**
When building a lambda function package, detect whether package-lock.json is already present and if so use `npm ci` command instead of `npm install` to install dependencies.

**Additional context**
The proposed command is available in npm since version 5.7.0
It seems like rather simple change in the current code, and I should be able to make a pull request once this gets accepted.