add test cases for path merge and other data clean patterns
diff --git a/genomix/genomix-pregelix/data/graphbuild.test/tip.txt b/genomix/genomix-pregelix/data/graphbuild.test/tip.txt
new file mode 100755
index 0000000..62a6fd7
--- /dev/null
+++ b/genomix/genomix-pregelix/data/graphbuild.test/tip.txt
@@ -0,0 +1,2 @@
+1	AATAGAAC

+2	GAAGGTCC