SGF-418 - Merge PR #83 updating the Spring IO Platform Plugin to perform compatibility checks.

Use the latest version of the Spring IO Plugin

Spring IO Platform 2.0 will remove the managed versions .properties
file as support for it has been removed in Spring Boot 1.3.

This commit moves the build onto a new version of the Spring IO Plugin
that uses the Maven bom rather than the properties file.
(cherry picked from commit a5b0850e7cc2e67e232e2a4e9f2adf34a9946b97)

Signed-off-by: John Blum <jblum@pivotal.io>

build.gradle

@@ -8,7 +8,7 @@ buildscript {
         classpath 'org.asciidoctor:asciidoctorj:1.5.0'
         classpath 'org.springframework.build.gradle:bundlor-plugin:0.1.2'
 		classpath 'org.springframework.build.gradle:propdeps-plugin:0.0.6'
-        classpath 'org.springframework.build.gradle:spring-io-plugin:0.0.3.RELEASE'
+        classpath 'io.spring.gradle:spring-io-plugin:0.0.4.RELEASE'
     }
 }
 
@@ -44,8 +44,12 @@ if (project.hasProperty('platformVersion')) {
         maven { url "https://repo.spring.io/libs-snapshot" }
     }
 
-    dependencies {
-      springIoVersions "io.spring.platform:platform-versions:${platformVersion}@properties"
+    dependencyManagement {
+        springIoTestRuntime {
+            imports {
+                mavenBom "io.spring.platform:platform-bom:${platformVersion}"
+            }
+        }
     }
 }