VOL-1558 Update vendored voltha-go and other items

Result of running dep ensure.  golang openolt now
builds.

Also update dockerfile to used specific alpine version

Change-Id: I1e5407e25bb0636a241a0650d1e44e5df567f44b
diff --git a/vendor/github.com/gyuho/goraph/.travis.yml b/vendor/github.com/gyuho/goraph/.travis.yml
new file mode 100644
index 0000000..4228e24
--- /dev/null
+++ b/vendor/github.com/gyuho/goraph/.travis.yml
@@ -0,0 +1,11 @@
+language: go
+
+sudo: false
+
+go:
+- 1.6
+- tip
+
+script:
+- ./test
+