[golangci-lint] refs fibercrypto#116 Exclude vendor to linter

.golangci.libcgo.yml

@@ -25,6 +25,7 @@ run:
   #   	vendor$, third_party$, testdata$, examples$, Godeps$, builtin$
   skip-dirs:
     - /usr/local/go/src
+    - vendor
 
   # which files to skip: they will be analyzed, but issues from them
   # won't be reported. Default value is empty list, but there is