Hyperparameters reversed in Scenario3

[maryamariyan]

From @justinormont on May 2, 2018, 8:51 AM PDT

Line below on file machinelearning/test/Microsoft.ML.Tests/Scenarios/Scenario3_SentimentPrediction.cs

CharFeatureExtractor = new NGramNgramExtractor() { NgramLength = 2, AllLengths = true },

Currently: (trigrams & unichargrams+bichargrams)

  CharFeatureExtractor = new NGramNgramExtractor() { NgramLength = 2, AllLengths = true },
  WordFeatureExtractor = new NGramNgramExtractor() { NgramLength = 3, AllLengths = false }

Should be: (unigram+bigram & trichargrams)

  CharFeatureExtractor = new NGramNgramExtractor() { NgramLength = 3, AllLengths = false },
  WordFeatureExtractor = new NGramNgramExtractor() { NgramLength = 2, AllLengths = true }