Adding a fake file to test revert in the autosubmit bot. (#2087)

diff --git a/auto_submit/test/validations/testfile.txt b/auto_submit/test/validations/testfile.txt
new file mode 100644
index 0000000..742283e
--- /dev/null
+++ b/auto_submit/test/validations/testfile.txt
@@ -0,0 +1 @@
+"hopefully this gets reverted."
\ No newline at end of file