Support upgrade of Spring Boot applications not using parent pom

[fabapp2]

Currently, the existence of a parent pom is expected.
This must not be the case, e.g. no parent pom but

            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>