add unittest; add --patch options

docs/cmd/hrp_postman2case.md

@@ -0,0 +1,26 @@
+## hrp postman2case
+
+convert postman collection to json/yaml testcase files
+
+### Synopsis
+
+convert postman collection to json/yaml testcase files
+
+```
+hrp postman2case $postman_path... [flags]
+```
+
+### Options
+
+```
+  -h, --help                help for postman2case
+  -d, --output-dir string   specify output directory, default to the same dir with postman collection file
+  -j, --to-json             convert to JSON format (default true)
+  -y, --to-yaml             convert to YAML format
+```
+
+### SEE ALSO
+
+* [hrp](hrp.md)	 - Next-Generation API Testing Solution.
+
+###### Auto generated by spf13/cobra on 12-May-2022