Merge pull request #415 from okue/spring-boot-version

Upgrade spring boot version to 2.2.1

Author: imasahiro

build.gradle

@@ -14,10 +14,15 @@
  * under the License.
  */
 
+import org.springframework.boot.gradle.plugin.SpringBootPlugin
+
 // ./gradlew clean && ./gradlew uploadArchives -Prelease
 
 buildscript {
-    ext.kotlin_version = '1.3.50'
+    ext {
+        kotlin_version = '1.3.50'
+        spring_boot_version = '2.2.1.RELEASE'
+    }
 
     repositories {
         mavenCentral()
@@ -32,7 +37,7 @@ buildscript {
         classpath 'io.franzbecker:gradle-lombok:3.1.0'
         classpath 'io.spring.gradle:dependency-management-plugin:1.0.8.RELEASE'
         classpath 'io.spring.gradle:propdeps-plugin:0.0.10.RELEASE'
-        classpath 'org.springframework.boot:spring-boot-gradle-plugin:2.2.1.RELEASE'
+        classpath "org.springframework.boot:spring-boot-gradle-plugin:$spring_boot_version"
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
@@ -94,7 +99,7 @@ subprojects {
 
     dependencyManagement {
         imports {
-            mavenBom 'org.springframework.boot:spring-boot-dependencies:2.2.0.RELEASE'
+            mavenBom SpringBootPlugin.BOM_COORDINATES
         }
 
         dependencies {
@@ -209,7 +214,7 @@ subprojects {
         options.compilerArgs << '-Xlint:all' << '-Xlint:deprecation' << '-Werror' << '-Xlint:-processing' << '-parameters'
     }
 
-    project.plugins.withType(org.springframework.boot.gradle.plugin.SpringBootPlugin) {
+    project.plugins.withType(SpringBootPlugin) {
         bootRun {
             systemProperties System.properties
         }