VOL-4268: Migration to BAL3.4.9.9 for voltha master and 2.8 branch

Change-Id: I66c77149524f2592fb018a3bc00dc9c8a8f94153
diff --git a/.gitignore b/.gitignore
index 56dc8a3..5200942 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,3 +44,6 @@
 agent/src/read_rxtx_power
 agent/read_rxtx_power
 eeprom.bin
+
+# downloaded Accton patch files and BAL packages
+agent/download/*