Fix typo in benchmark

Author: dgrnbrg

.travis.yml

@@ -5,5 +5,5 @@ env:
     matrix:
         - TEST_CMD='lein test'
         - TEST_CMD='lein bench output --data-structure fractal -- --data-structure b-tree -- --data-structure sorted-set'
-        - TEST_CMD='lein bench output -d forward -- --d reverse -- -d shuffle -- -d zero'
+        - TEST_CMD='lein bench output --delete-pattern forward -- --delete-pattern reverse -- --delete-pattern shuffle -- --delete-pattern zero'
 script: $TEST_CMD