Added default repo.url to the servlet sample POM.

Author: Tracy Boehrer

samples/servlet-echo/pom.xml

@@ -32,6 +32,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.deploy.skip>false</maven.deploy.skip>
+        <repo.url>https://botbuilder.myget.org/F/scratch/maven/</repo.url>
     </properties>
 
     <dependencies>