When all dependencies are removed/unchecked from a boot project. The edit starters tends to create a broken project because it does not ensure that at leats a dependency like:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>

Steps to reproduce:

1. create a project with "new Spring starter". Select a single dependency (e.g. web).
2. Use "Edit starters" and remove the dependency.

=> The dependency is removed from the pom leaving no dependencies in the pom at all.

The project is now broken and has compile errors.

Expected behavior is that upon removal of the last dependency we ensure that at least a dependency on
the 'base' spring-boot-starter dependency exists. If it doesn't it should be added.