Upgrade to go v1.11.5

Author: tanx

.travis.yml

@@ -15,7 +15,7 @@ env:
   global:
     - LND_TAG=cfb5e249b9d6dae9e44dcf56c29c3eda531290fe
     - BTCD_TAG=306aecffea325e97f513b3ff0cf7895a5310651d
-    - GO_TAG=1.11.4
+    - GO_TAG=1.11.5
     - GOROOT=$HOME/go
     - GOPATH=$HOME/gocode
     - PATH=$GOPATH/bin:$GOROOT/bin:$PATH