venv: add fabric to venv requirements

BUG=chromium:778025
TEST=bin/python_venv -c 'import fabric; print fabric.__file__'

Change-Id: Iac23b65fa62d2f66deb882334fa9062bb7685c71
Reviewed-on: https://chromium-review.googlesource.com/736689
Commit-Ready: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Allen Li <ayatane@chromium.org>
diff --git a/venv/requirements.txt b/venv/requirements.txt
index 46f3004..33d7081 100644
--- a/venv/requirements.txt
+++ b/venv/requirements.txt
@@ -2,6 +2,7 @@
 coverage==4.4.1
 Django==1.5.1
 enum34==1.1.6
+fabric==1.12.0
 funcsigs==1.0.2
 mock==2.0.0
 oauth2client==3.0.0