title: No FileSystem for scheme: s3 with pyspark
body: <p>I'm trying to read a txt file from S3 with Spark, but I'm getting thhis error:</p>
  
  <pre><code>No FileSystem for scheme: s3
  </code></pre>
  
  <p>This is my code:</p>
  
  <pre><code>from pyspark import SparkContext, SparkConf
  conf = SparkConf().setAppName("first")
  sc = SparkContext(conf=conf)
  data = sc.textFile("s3://"+AWS_ACCESS_KEY+":" + AWS_SECRET_KEY + "@/aaa/aaa/aaa.txt")
  
  header = data.first()
  </code></pre>
  
  <p>This is the full traceback:</p>
  
  <pre><code>An error occurred while calling o25.partitions.
  : java.io.IOException: No FileSystem for scheme: s3
      at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)
      at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
      at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)
      at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)
      at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)
      at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)
      at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
      at org.apache.hadoop.mapred.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:258)
      at org.apache.hadoop.mapred.FileInputFormat.listStatus(FileInputFormat.java:229)
      at org.apache.hadoop.mapred.FileInputFormat.getSplits(FileInputFormat.java:315)
      at org.apache.spark.rdd.HadoopRDD.getPartitions(HadoopRDD.scala:194)
      at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
      at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
      at scala.Option.getOrElse(Option.scala:121)
      at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
      at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:35)
      at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:252)
      at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:250)
      at scala.Option.getOrElse(Option.scala:121)
      at org.apache.spark.rdd.RDD.partitions(RDD.scala:250)
      at org.apache.spark.api.java.JavaRDDLike$class.partitions(JavaRDDLike.scala:61)
      at org.apache.spark.api.java.AbstractJavaRDDLike.partitions(JavaRDDLike.scala:45)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
      at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
      at py4j.Gateway.invoke(Gateway.java:280)
      at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
      at py4j.commands.CallCommand.execute(CallCommand.java:79)
      at py4j.GatewayConnection.run(GatewayConnection.java:214)
      at java.lang.Thread.run(Thread.java:748)
  </code></pre>
  
  <p>How can I fix this?</p>