Add github.com/krishicks/yaml-patch to vendor

vendor/github.com/krishicks/yaml-patch/README.md

@@ -0,0 +1,86 @@
+# yaml-patch
+
+`yaml-patch` is a version of Evan Phoenix's
+[json-patch](https://github.com/evanphx/json-patch), which is an implementation
+of [JavaScript Object Notation (JSON) Patch](https://tools.ietf.org/html/rfc6902),
+but for YAML.
+
+
+## Installing
+
+`go get github.com/krishicks/yaml-patch`
+
+If you want to use the CLI:
+
+`go get github.com/krishicks/yaml-patch/cmd/yaml-patch`
+
+## API
+
+Given the following RFC6902-ish YAML document, `ops`:
+
+```
+---
+- op: add
+  path: /baz/waldo
+  value: fred
+```
+
+And the following YAML that is to be modified, `src`:
+
+```
+---
+foo: bar
+baz:
+  quux: grault
+```
+
+Decode the ops file into a patch:
+
+```
+patch, err := yamlpatch.DecodePatch(ops)
+// handle err
+```
+
+Then apply that patch to the document:
+
+```
+dst, err := patch.Apply(src)
+// handle err
+
+// do something with dst
+```
+
+### Example
+
+```
+doc := []byte(`---
+foo: bar
+baz:
+  quux: grault
+`)
+
+ops := []byte(`---
+- op: add
+  path: /baz/waldo
+  value: fred
+`)
+
+patch, err := yamlpatch.DecodePatch(ops)
+if err != nil {
+  log.Fatalf("decoding patch failed: %s", err)
+}
+
+bs, err := patch.Apply(doc)
+if err != nil {
+  log.Fatalf("applying patch failed: %s", err)
+}
+
+fmt.Println(string(bs))
+```
+
+```
+baz:
+  quux: grault
+  waldo: fred
+foo: bar
+```