VOL-2006 update voltha-api-server to use go mod

Change-Id: Ic9cce461175dd08cc4f30ddda2172640e8928b00
diff --git a/vendor/github.com/pierrec/lz4/.travis.yml b/vendor/github.com/pierrec/lz4/.travis.yml
index 658910d..b2c806d 100644
--- a/vendor/github.com/pierrec/lz4/.travis.yml
+++ b/vendor/github.com/pierrec/lz4/.travis.yml
@@ -1,13 +1,9 @@
 language: go
 
-env:
-  - GO111MODULE=off
-  - GO111MODULE=on
-
 go:
+  - 1.8.x
   - 1.9.x
   - 1.10.x
-  - 1.11.x
   - master
 
 matrix:
@@ -20,5 +16,3 @@
 script: 
  - go test -v -cpu=2
  - go test -v -cpu=2 -race
- - go test -v -cpu=2 -tags noasm
- - go test -v -cpu=2 -race -tags noasm