[mllib] All updates for MLlib for QA for Spark 1.2

Major additions:
* added Python tests
* updated tests to do JSON logging
* updated test settings to be more reasonable for QA
* split Scala tests into directories for Spark 1.0, 1.1, 1.2 (since APIs are incompatible)
 * Note: These could share some code, but it is unclear how much we need to support spark-perf for more than the latest 1 or 2 versions of MLlib.

Items remaining (before next Spark release QA period):
* Change Scala testName to match Python test names: “glm-regression” —> GLMRegressionTest
* Make parameter names match. (num-examples, num-rows, etc.)
* Refactor correlation tests so pearson/spearman is a parameter.
* Better data generation in Python

Author: Joseph K. Bradley <joseph@databricks.com>
Author: Joseph K. Bradley <joseph.kurata.bradley@gmail.com>

Closes #29 from jkbradley/qa-1-2 and squashes the following commits:

fde1fef [Joseph K. Bradley] removed mllib from travis.yml since it requires a snapshot of spark
b09b7cb [Joseph K. Bradley] fixed typo
6278838 [Joseph K. Bradley] removed qa config files
e9770eb [Joseph K. Bradley] code cleanups
5a28969 [Joseph K. Bradley] updated config for mllib
802588e [Joseph K. Bradley] added other python tests: kmeans, naive bayes, pearson, spearman
eea334a [Joseph K. Bradley] updated glm debug config
7b1d4b6 [Joseph K. Bradley] removed boosting from spark-perf because of api change.  updated randomforest to fit api change. updated glmdebug config
478fec9 [Joseph K. Bradley] fixed glm debug config
748c97b [Joseph K. Bradley] Added config file for debugging Python regressions.
5b47f34 [Joseph K. Bradley] updated pyspark tests to cache trainRDD before computing testTime on it, to match Scala code
912d641 [Joseph K. Bradley] removed config for als python since we will use the same settings as for scala
1759ddb [Joseph K. Bradley] fixed python json logging to match scala
6335851 [Joseph K. Bradley] made separate python config files since those tests take much longer
3d2b197 [Joseph K. Bradley] updated so shuffle manager is only specified for mllib
a4735bd [Joseph K. Bradley] fixed als and json logging for spark 1.1 python tests
3247fe1 [Joseph K. Bradley] added shuffle manager option to all config files this time
55630e1 [Joseph K. Bradley] Added json logging for python mllib tests
26f2d49 [Joseph K. Bradley] decreased svd test size config
05524cc [Joseph K. Bradley] json logging now in all of mllib tests.  fixed decision tree test bug for 1.2
95af6cd [Joseph K. Bradley] added json logging for mllib tests for spark 1.1
160f79f [Joseph K. Bradley] added json logging for mllib tests for spark 1.2.  need to do 1.1 and 1.0 still
ad44fac [Joseph K. Bradley] fixed naive bayes config.  fixed loss for mllib_test.py regression test
81d9ae4 [Joseph K. Bradley] fixed config file
0ce6405 [Joseph K. Bradley] updated config scripts for mllib
7bf7210 [Joseph K. Bradley] fixed python mllib als test
cd3f0d2 [Joseph K. Bradley] added python mllib als test
c8d016a [Joseph K. Bradley] added pyspark mllib glm regression test
fb37915 [Joseph K. Bradley] fixed pyspark mllib glm classification test
d9d1ce9 [Joseph K. Bradley] added initial pyspark mllib test but not yet tested
b900032 [Joseph K. Bradley] changed als test to set blocks to num rdd partitions
517b861 [Joseph K. Bradley] updated config files
dda5c17 [Joseph K. Bradley] added base config for qa for 1.1
645eaf6 [Joseph K. Bradley] updated config.py.template
1da771f [Joseph K. Bradley] Major refactoring of MLlib part of spark-perf. * Added structure to GLM part of tests, eliminating some code * Added 3 separate directories with complete tests for Spark 1.0, 1.1, 1.2 * Added GradientBoosting test as part of DecisionTreeTests
7ecd2c5 [Joseph K. Bradley] Updated DecisionTree test config options to a reasonable QA set. Added SNAPSHOT suffix to MLlibTestsBuild.scala for onepointone.  Fixed mllib jar name in testsuites.py.  Updated to use WeightedEnsembleModel instead of RandomForestModel.  Updated cluster.py slave file check.
04ff018 [Joseph K. Bradley] fixed off-by-one bug in computing median
841052c [Joseph K. Bradley] Fixed bug in loading data for DecisionTree tests (training data was loaded as test data)
00bdbcf [Joseph K. Bradley] Added DecisionTree test options to support testing on a real dataset: * training-data, test-data: training, test dataset paths or URIs Also added DecisionTree test option: * test-data-fraction: fraction of data to hold out for training (used for both real & synthetic data)
c39b32a [Joseph K. Bradley] prep to merge with master
c53c685 [Joseph K. Bradley] removed streaming tests, added DT one
e6553f3 [Joseph K. Bradley] Updated DecisionTree test to take featureSubsetStrategy parameter.
6ed8ad2 [Joseph K. Bradley] Updated to run RandomForest with numTrees parameter