fix: call fs.createReadStream lazily

lib/interceptor.js

@@ -198,10 +198,12 @@ module.exports = class Interceptor {
     if (!fs) {
       throw new Error('No fs')
     }
-    const readStream = fs.createReadStream(filePath)
-    readStream.pause()
     this.filePath = filePath
-    return this.reply(statusCode, readStream, headers)
+    return this.reply(statusCode, () =>  {
+      const readStream = fs.createReadStream(filePath)
+      readStream.pause()
+      return readStream
+    }, headers)
   }
 
   // Also match request headers
@@ -453,15 +455,6 @@ module.exports = class Interceptor {
   markConsumed() {
     this.interceptionCounter++
 
-    if (
-      (this.scope.shouldPersist() || this.counter > 0) &&
-      this.interceptionCounter > 1 &&
-      this.filePath
-    ) {
-      this.body = fs.createReadStream(this.filePath)
-      this.body.pause()
-    }
-
     remove(this)
 
     if (!this.scope.shouldPersist() && this.counter < 1) {