Make ctx backward compatible with 9.0.0

Author: JohnAlbin

index.js

@@ -127,6 +127,8 @@ function withConfigLoader(cb) {
         } else {
           configPath = file.dirname
         }
+        // @TODO: The options property is deprecated and should be removed in 10.0.0.
+        contextOptions.options = Object.assign({}, contextOptions)
         contextOptions.file = file
         return postcssLoadConfig(
           contextOptions,

test.js

@@ -329,7 +329,8 @@ describe('PostCSS Guidelines', function () {
     stream.on('data', function () {
       assert.deepEqual(postcssLoadConfigStub.getCall(0).args[0], {
         file: file,
-        to: 'initial'
+        to: 'initial',
+        options: { to: 'initial' }
       })
       assert.equal(postcssStub.use.getCall(0).args[0], plugins)
       assert.equal(postcssStub.process.getCall(0).args[1].to, 'overriden')