add event and API endpoint to get the contract sourcecode

lib/pipeline/pipeline.js

@@ -19,6 +19,24 @@ class Pipeline {
     this.logger = options.logger;
     this.plugins = options.plugins;
     this.pipelinePlugins = this.plugins.getPluginsFor('pipeline');
+
+    const self = this;
+    self.events.setCommandHandler("files:contract", (filename, cb) => {
+      let file = self.contractsFiles.find((file) => file.filename === filename);
+      if (!file) {
+        return cb({error: filename + " not found"});
+      }
+      file.content(cb);
+    });
+
+    let plugin = this.plugins.createPlugin('deployment', {});
+    plugin.registerAPICall(
+      'get',
+      '/embark/files/contracts/',
+      (req, res) => {
+        self.events.request('files:contract', req.query.filename, res.send.bind(res));
+      }
+    );
   }
 
   build(abi, contractsJSON, path, callback) {