Support custom config file path, close: #23 (#24)

* Support custom config file path, close: /issues/23

* format example config as json

* v2.0.1

Author: leecade

README.md

@@ -25,6 +25,26 @@ babel configuration:
 }
 ```
 
+With config:
+
+```json
+{
+  "plugins": [
+    ["styled-jsx/babel", {
+      "plugins": [
+        [
+          "styled-jsx-plugin-postcss",
+          {
+            "path":
+              "[PATH_PREFIX]/postcss.config.js"
+          }
+        ]
+      ] 
+    }]
+  ]
+}
+```
+
 ### Example with CRA
 
 Usage with Create React App requires you to either _eject_ or use [react-app-rewired](https://github.com/timarney/react-app-rewired). 

index.js

@@ -14,7 +14,7 @@ module.exports = (css, settings) => {
     wait = false
   }
 
-  processor(cssWithPlaceholders)
+  processor(cssWithPlaceholders, settings)
     .then(resolved)
     .catch(resolved)
   loopWhile(() => wait)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "styled-jsx-plugin-postcss",
-  "version": "2.0.0",
+  "version": "2.0.1",
   "description": "Plugin to add PostCSS support to styled-jsx",
   "main": "index.js",
   "scripts": {

processor.js

@@ -9,7 +9,7 @@ function processor(src, options) {
 
   let loaderPromise
   if (!plugins) {
-    loaderPromise = loader(options.env || process.env, null, { argv: false })
+    loaderPromise = loader(options.env || process.env, options.path, { argv: false })
       .then(pluginsInfo => {
         plugins = pluginsInfo.plugins || []
       })