Use mod vendor for vendored directory (backwards compatible)

vendor/github.com/russross/blackfriday/.travis.yml

@@ -0,0 +1,30 @@
+sudo: false
+language: go
+go:
+  - 1.5.4
+  - 1.6.2
+  - tip
+matrix:
+  include:
+    - go: 1.2.2
+      script:
+        - go get -t -v ./...
+        - go test -v -race ./...
+    - go: 1.3.3
+      script:
+        - go get -t -v ./...
+        - go test -v -race ./...
+    - go: 1.4.3
+      script:
+        - go get -t -v ./...
+        - go test -v -race ./...
+  allow_failures:
+    - go: tip
+  fast_finish: true
+install:
+  - # Do nothing. This is needed to prevent default install action "go get -t -v ./..." from happening here (we want it to happen inside script step).
+script:
+  - go get -t -v ./...
+  - diff -u <(echo -n) <(gofmt -d -s .)
+  - go tool vet .
+  - go test -v -race ./...