ZEPPELIN-55 Make tutorial notebook independent from filesystem.

[Leemoonsoo]

Tutorial notebook is downloading data using wget and unzip and load the csv file.
This works only in local-mode and not going to work with cluster deployments.

Discussed solution in the issue ZEPPELIN-55 are

• Upload data to HDFS
• Upload data to S3

However, not all user will install HDFS, and accessing S3 via hdfs client needs accessKey and secretKey in configuration.

this PR make tutorial notebook independent from any filesystem, by reading data from http(s) address and parallelize directly.

Here's how this PR loads data

// load bank data
val bankText = sc.parallelize(
    IOUtils.toString(
        new URL("https://s3.amazonaws.com/apache-zeppelin/tutorial/bank/bank.csv"),
        Charset.forName("utf8")).split("\n"))

case class Bank(age: Integer, job: String, marital: String, education: String, balance: Integer)

val bank = bankText.map(s => s.split(";")).filter(s => s(0) != "\"age\"").map(
    s => Bank(s(0).toInt, 
            s(1).replaceAll("\"", ""),
            s(2).replaceAll("\"", ""),
            s(3).replaceAll("\"", ""),
            s(5).replaceAll("\"", "").toInt
        )
).toDF()
bank.registerTempTable("bank")

[Leemoonsoo]

Ready to merge

[Leemoonsoo]

Merging if there're no more discussions.