Added dump_failures command doc (#26)

Co-authored-by: remi288 <remizcode200@yahoo.com>

docs/dump_failures.rst

@@ -0,0 +1,29 @@
+Dump Failures
+**************************
+
+This script will display information about failing tests given a push.
+
+DUMP_FAILURES_EDIT_COMMAND
+=========================
+This is an environment variable in ``dump_failures`` file that is needed to be set to automatically open failures in vim.
+
+How to set Environment Variable
+-------------------------
+
+At the command line:
+
+>>> export DUMP_FAILURES_EDIT_COMMAND="vim +/{test} +:vnew +':let f=append(1,{context})' /path/to/mozilla-central/{manifest}"
+
+Run ``dump_failures`` file in terminal using citools
+
+ >>> citools push failures arg=branch arg=rev
+
+ Expected output:
+
+ display failures in vim
+
+
+
+
+
+