add servlet initializer for apollo-portal and apollo-adminservice

apollo-adminservice/src/main/java/com/ctrip/framework/apollo/adminservice/ServletInitializer.java

+package com.ctrip.framework.apollo.adminservice;
+
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+/**
+ * Entry point for traditional web app
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ServletInitializer extends SpringBootServletInitializer {
+
+  @Override
+  protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+    return application.sources(AdminServiceApplication.class);
+  }
+
+}

apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/ServletInitializer.java

+package com.ctrip.framework.apollo.portal;
+
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+/**
+ * Entry point for traditional web app
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ServletInitializer extends SpringBootServletInitializer {
+
+  @Override
+  protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+    return application.sources(PortalApplication.class);
+  }
+
+}