remove slice from airbase

There is a circular dependency here because slice uses airbase as
a parent, but airbase specifies slice as a dependency

airbase/pom.xml

@@ -197,7 +197,6 @@
         <dep.hamcrest.version>1.3</dep.hamcrest.version>
         <dep.mockito.version>1.9.5</dep.mockito.version>
         <dep.objenesis.version>1.3</dep.objenesis.version>
-        <dep.slice.version>0.38-SNAPSHOT</dep.slice.version>
         <dep.jmh.version>1.20</dep.jmh.version>
 
         <!-- license headers -->
@@ -1303,12 +1302,6 @@
                 <artifactId>objenesis</artifactId>
                 <version>${dep.objenesis.version}</version>
             </dependency>
-
-            <dependency>
-                <groupId>com.facebook.airlift</groupId>
-                <artifactId>slice</artifactId>
-                <version>${dep.slice.version}</version>
-            </dependency>
         </dependencies>
     </dependencyManagement>