Add missing test resources

Change-Id: I18dce6f191dee6c9784e250c1ac116899b5dedcd
diff --git a/src/test/resources/simple_3gram.freq b/src/test/resources/simple_3gram.freq
new file mode 100644
index 0000000..1b36950
--- /dev/null
+++ b/src/test/resources/simple_3gram.freq
@@ -0,0 +1,6 @@
+alex	bin	ich	1
+bin	alex	.	1
+bin	ich	.	1
+heiße	alex	.	1
+ich	bin	alex	1
+ich	heiße	alex	1