Remove Mock Accumulo (#536)

* Remove Mock from Proxy (#452) and Shell
* Move ShellTest to ShellIT to use Mini (may be redundant with some of
  ShellServerIT's tests)
* Make KerberosTokenEmbeddedKDCTest use a volatile to avoid a transient
  build failure while testing this change

client/mapreduce/src/main/java/org/apache/accumulo/core/client/mapreduce/RangeInputSplit.java

@@ -144,12 +144,6 @@ public void readFields(DataInput in) throws IOException {
       localIterators = in.readBoolean();
     }
 
-    // ignore mock flag; it was removed
-    if (in.readBoolean()) {
-      throw new IllegalStateException(
-          "Mock flag was set in serialized RangeInputSplit, but mock Accumulo was removed");
-    }
-
     if (in.readBoolean()) {
       int numColumns = in.readInt();
       List<String> columns = new ArrayList<>(numColumns);
@@ -201,9 +195,6 @@ public void write(DataOutput out) throws IOException {
       out.writeBoolean(localIterators);
     }
 
-    // should be false to indicate that no mock flag was serialized; mock was removed
-    out.writeBoolean(false);
-
     out.writeBoolean(null != fetchedColumns);
     if (null != fetchedColumns) {
       String[] cols = InputConfigurator.serializeColumns(fetchedColumns);

core/pom.xml

@@ -192,7 +192,6 @@
                 <exclude>.*[.]impl[.].*</exclude>
                 <exclude>.*[.]thrift[.].*</exclude>
                 <exclude>org[.]apache[.]accumulo[.]core[.]security[.]crypto[.].*</exclude>
-                <exclude>org[.]apache[.]accumulo[.]core[.]client[.]mock[.].*</exclude>
               </excludes>
               <allows>
                 <!--Allow API data types to reference thrift types, but do not

core/src/main/findbugs/exclude-filter.xml

@@ -58,7 +58,6 @@
       <Class name="org.apache.accumulo.core.util.AddressUtil" />
       <Class name="org.apache.accumulo.core.zookeeper.ZooUtil" />
       <Class name="org.apache.accumulo.core.security.VisibilityConstraint" />
-      <Class name="org.apache.accumulo.core.client.mock.IteratorAdapter" />
     </Or>
     <Or>
       <Bug code="NM" pattern="NM_SAME_SIMPLE_NAME_AS_SUPERCLASS" />