fix build process on windows

lib/contracts/code_generator.js

@@ -289,6 +289,7 @@ class CodeGenerator {
         });
       },
       function getImports(web3Location, next) {
+        web3Location = web3Location.replace(/\\/g, '/'); // Import paths must always have forward slashes
         code += "\nimport Web3 from '" + web3Location + "';\n";
         code += "\nimport web3 from 'Embark/web3';\n";
         next();

lib/index.js

@@ -3,6 +3,15 @@ let async = require('async');
 
 require('colors');
 
+// Override process.chdir so that we have a partial-implementation PWD for Windows
+const realChdir = process.chdir;
+process.chdir = (...args) => {
+    if (!process.env.PWD) {
+        process.env.PWD = process.cwd();
+    }
+    realChdir(...args);
+};
+
 let Engine = require('./core/engine.js');
 
 let version = require('../package.json').version;

lib/pipeline/pipeline.js

@@ -288,6 +288,7 @@ class Pipeline {
         });
       },
       function getImports(web3Location, next) {
+        web3Location = web3Location.replace(/\\/g, '/'); // Import paths must always have forward slashes
         code += "\nimport Web3 from '" + web3Location + "';\n";
 
         code += "\n if (typeof web3 !== 'undefined') {";