Make the CombinedConfig.getVal function more tolerant of non-string values.

cliutils.nim

@@ -15,7 +15,16 @@ proc getVal*(cfg: CombinedConfig, key, default: string): string =
 
   if cfg.docopt[argKey]: return $cfg.docopt[argKey]
   elif existsEnv(envKey): return getEnv(envKey)
-  elif cfg.json.hasKey(jsonKey): return cfg.json[jsonKey].getStr
+  elif cfg.json.hasKey(jsonKey):
+    let node = cfg.json[jsonKey]
+    case node.kind
+    of JString: return node.getStr
+    of JInt: return $node.getInt
+    of JFloat: return $node.getFloat
+    of JBool: return $node.getBool
+    of JNull: return ""
+    of JObject: return $node
+    of JArray: return $node
   else: return default