Removed all the livy prefixes from directories

It seemed redundant to have the livy prefixes
on all the directories. We are still keeping
the livy- prefix for the jar files.

bin/setup-classpath

@@ -18,7 +18,7 @@
 
 LIBDIR="$LIVY_HOME/jars"
 if [ ! -d "$LIBDIR" ]; then
-  LIBDIR="$LIVY_HOME/livy-assembly/target/jars"
+  LIBDIR="$LIVY_HOME/assembly/target/jars"
 fi
 if [ ! -d "$LIBDIR" ]; then
   echo "Could not find Livy jars directory." 1>&2

pom.xml

@@ -116,15 +116,15 @@
   </repositories>
 
   <modules>
-    <module>livy-api</module>
-    <module>livy-assembly</module>
-    <module>livy-core</module>
-    <module>livy-repl</module>
-    <module>livy-server</module>
-    <module>livy-spark</module>
-    <module>livy-yarn</module>
-    <module>livy-client-local</module>
-    <module>livy-client-http</module>
+    <module>api</module>
+    <module>assembly</module>
+    <module>core</module>
+    <module>repl</module>
+    <module>server</module>
+    <module>spark</module>
+    <module>yarn</module>
+    <module>client-local</module>
+    <module>client-http</module>
   </modules>
 
   <dependencyManagement>