VOL-1868 move simulated onu from voltha-go to voltha-simonu-adapter

Sourced from voltha-go commit 251a11c0ffe60512318a644cd6ce0dc4e12f4018

Change-Id: Iab179bc2f3dd772ed7f488d1c03d1a84ba75e874
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2b29f27
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+tests