Use pagedjs from require

This is to fix issue #2

index.js

@@ -11,9 +11,9 @@ const app = express();
 
 const PORT = 9999;
 
-let dir = process.cwd();
-
-let scriptPath = path.resolve(dir, "./node_modules/pagedjs/dist/");
+let currentDir = process.cwd();
+let pagedjsPath = require.resolve('pagedjs')
+let scriptPath = path.resolve(pagedjsPath, '../../dist')
 
 const PDF_SETTINGS = {
   printBackground: true,
@@ -42,12 +42,13 @@ class Printer extends EventEmitter {
   }
 
   async serve(input) {
-    let relativePath = path.resolve(dir, input);
+    let relativePath = path.resolve(currentDir, input);
     let dirname = path.dirname(relativePath);
 
     app.use("/print", express.static(dirname))
 
-    let scriptPath = path.resolve(dir, "./node_modules/pagedjs/dist/");
+    let pagedjsPath = require.resolve('pagedjs')
+    let scriptPath = path.resolve(pagedjsPath, '../../dist')
     app.use("/polyfill", express.static(scriptPath))
 
     app.set('port', process.env.PORT || 0);
@@ -74,7 +75,7 @@ class Printer extends EventEmitter {
     let server = await this.serve(input);
     let port = server.address().port;
 
-    let relativePath = path.resolve(dir, input);
+    let relativePath = path.resolve(currentDir, input);
     let basename = path.basename(relativePath);
 
     await page.goto(`http://localhost:${port}/print/${basename}`)