Bump springBootVersion from 2.2.6.RELEASE to 2.2.7.RELEASE

Bumps `springBootVersion` from 2.2.6.RELEASE to 2.2.7.RELEASE.

Updates `spring-boot-dependencies` from 2.2.6.RELEASE to 2.2.7.RELEASE
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](https://github.com/spring-projects/spring-boot/compare/v2.2.6.RELEASE...v2.2.7.RELEASE)

Updates `spring-boot-configuration-processor` from 2.2.6.RELEASE to 2.2.7.RELEASE
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](https://github.com/spring-projects/spring-boot/compare/v2.2.6.RELEASE...v2.2.7.RELEASE)

Updates `spring-boot-autoconfigure-processor` from 2.2.6.RELEASE to 2.2.7.RELEASE
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](https://github.com/spring-projects/spring-boot/compare/v2.2.6.RELEASE...v2.2.7.RELEASE)

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

build.gradle

@@ -24,7 +24,7 @@ ext {
         mybatisSpringVersion = '2.0.4',
         mybatisSpringBootStarterVersion = '2.1.2',
         springVersion = '5.2.6.RELEASE',
-        springBootVersion = '2.2.6.RELEASE',
+        springBootVersion = '2.2.7.RELEASE',
         jsqlparserVersion = '3.1',
         junitVersion = '5.6.2',
     ]