Bump spring-boot-maven-plugin (testcontainers#1148)

Bumps [spring-boot-maven-plugin](https://github.com/spring-projects/spring-boot) from 2.1.1.RELEASE to 2.1.2.RELEASE.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.1.1.RELEASE...v2.1.2.RELEASE)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot[bot]

examples/spring-boot/pom.xml

@@ -50,7 +50,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
-                <version>2.1.1.RELEASE</version>
+                <version>2.1.2.RELEASE</version>
             </plugin>
         </plugins>
     </build>