Update classpath.sh to include instrument package

Co-authored-by: Yuqi Huai (@YuqiHuai)

Fixes broken tutorial instructions (#233)

scripts/classpath.sh

@@ -8,11 +8,18 @@ popd > /dev/null
 # The root dir is one up
 ROOT_DIR=`dirname $SCRIPT_DIR`
 
-# Create classpath
+# Create classpath using all classes from and dependencies of the `fuzz` and `instrument` packages
+
 cp="$ROOT_DIR/fuzz/target/classes:$ROOT_DIR/fuzz/target/test-classes"
 
 for jar in $ROOT_DIR/fuzz/target/dependency/*.jar; do
   cp="$cp:$jar"
 done
 
+cp="$cp:$ROOT_DIR/instrument/target/classes:$ROOT_DIR/instrument/target/test-classes"
+
+for jar in $ROOT_DIR/instrument/target/dependency/*.jar; do
+  cp="$cp:$jar"
+done
+
 echo $cp