Build fixes for Maven

libraries/botbuilder-schema/pom.xml

@@ -42,4 +42,17 @@
           <version>RELEASE</version>
       </dependency>
   </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.7.0</version>
+        <configuration>
+          <source>1.8</source>
+          <target>1.8</target>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
 </project>

pom.xml

@@ -5,6 +5,8 @@
   <artifactId>bot-parent</artifactId>
   <version>4.0.0</version>
   
+  <packaging>pom</packaging>
+  
   <name>Microsoft BotBuilder SDK Parent</name>
   <description>This package contains the parent module of Microsoft BotBuilder SDK.</description>
   <url>https://github.com/Microsoft/botbuilder-java</url>