plugin: Allow both array as well as object params in example plugin

Signed-off-by: Christian Decker <decker.christian@gmail.com>

contrib/plugins/helloworld.py

@@ -1,10 +1,10 @@
 #!/usr/bin/env python3
 """Simple plugin to show how to build new plugins for c-lightning
 
-It demonstrates how a plugin communicates with c-lightning, how it registers
-command line arguments that should be passed through and how it can register
-JSON-RPC commands. We communicate with the main daemon through STDIN and STDOUT,
-reading and writing JSON-RPC requests.
+It demonstrates how a plugin communicates with c-lightning, how it
+registers command line arguments that should be passed through and how
+it can register JSON-RPC commands. We communicate with the main daemon
+through STDIN and STDOUT, reading and writing JSON-RPC requests.
 
 """
 import json
@@ -14,8 +14,8 @@ import sys
 greeting = "World"
 
 
-def json_hello(request):
-    greeting = "Hello {}".format(request['params']['name'])
+def json_hello(request, name):
+    greeting = "Hello {}".format(name)
     return greeting
 
 
@@ -37,7 +37,7 @@ def json_getmanifest(request):
     }
 
 
-def json_init(request):
+def json_init(request, options):
     """The main daemon is telling us the relevant cli options
     """
     global greeting
@@ -52,14 +52,23 @@ methods = {
     'init': json_init,
 }
 
+
 partial = ""
 for l in sys.stdin:
     partial += l
     try:
         request = json.loads(partial)
+        result = None
+        method = methods[request['method']]
+        params = request['params']
+        if isinstance(params, dict):
+            result = method(request, **params)
+        else:
+            result = method(request, *params)
+
         result = {
             "jsonrpc": "2.0",
-            "result": methods[request['method']](request),
+            "result": result,
             "id": request['id']
         }
         json.dump(result, fp=sys.stdout)