Remove duplicate versions

These versions are inherited from opendaylight parent
poms. Removing the override for these inherited versions.

Change-Id: I83b374e4d8815e21fd48bedbe4dd46bc246e44a4
Signed-off-by: Patrick Brady <patrick.brady@att.com>
Issue-ID: APPC-1355
diff --git a/appc-sequence-generator/appc-sequence-generator-model/pom.xml b/appc-sequence-generator/appc-sequence-generator-model/pom.xml
index 2bc3457..146bae2 100644
--- a/appc-sequence-generator/appc-sequence-generator-model/pom.xml
+++ b/appc-sequence-generator/appc-sequence-generator-model/pom.xml
@@ -3,7 +3,7 @@
  ============LICENSE_START=======================================================
  ONAP : APPC
  ================================================================================
- Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ Copyright (C) 2017-2019 AT&T Intellectual Property. All rights reserved.
  ================================================================================
  Copyright (C) 2017 Amdocs
  =============================================================================
@@ -51,7 +51,6 @@
             <plugin>
                 <groupId>org.opendaylight.yangtools</groupId>
                 <artifactId>yang-maven-plugin</artifactId>
-                <version>${odl.yangtools.version}</version>
                 <dependencies>
                     <dependency>
                         <groupId>org.opendaylight.mdsal</groupId>
@@ -98,12 +97,10 @@
     <dependency>
       <groupId>org.opendaylight.mdsal.model</groupId>
       <artifactId>ietf-inet-types</artifactId>
-      <version>${odl.ietf-inet-types.version}</version>
     </dependency>
     <dependency>
       <groupId>org.opendaylight.mdsal.model</groupId>
       <artifactId>ietf-yang-types</artifactId>
-      <version>${odl.ietf-yang-types.version}</version>
     </dependency>
   </dependencies>
 </project>