update example app pom with spring-boot starter parent (#38)

Author: tapaderster

example/pom.xml

@@ -2,6 +2,12 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.0.5.RELEASE</version>
+        <relativePath/>
+    </parent>
 
     <groupId>com.expedia.www</groupId>
     <artifactId>graphql-kotlin-example</artifactId>