Using springboot starter POMs for development and production

Why do most example projects for Springboot use starter POMs without a version? The documentation makes no mention of what version is being used.

For instance, using web starter without a version...

compile "org.springframework.boot:spring-boot-starter-web" 

...I'm assuming pulls the latest snapshot based on the POM? I suppose that's convenient for development, but then again, I've never used dependencies without a version number, so this feels strange.

Is it safe to use starter packages for production if I configure the dependency with a specific version, such as the example below, or should starters be used for development only?

  compile "org.springframework.boot:spring-boot-starter-web:1.2.1"