TFoS Support

[allwefantasy]

What changes are proposed in this pull request?

Adding some kinds of Running mode. For now, it support "Normal" and "TFos"

Here is the code show how it works:

estimator = TFTextFileEstimator(inputCol="sentence_matrix", outputCol="sentence_matrix", labelCol="preds",
                                fitParam=[{"epochs": 1, "cluster_size": 2, "batch_size": 1, "model": "/tmp/model"}],
                                runningMode="TFoS",
                                mapFnParam=map_fun)

When runningMode is set to Normal, this means tensorflow will be invode with the number of fitParam's size and they do have the same training data but with diffrent fitParam and multi model will be saved.

When runningMode is set to TFoS, this means a tensorflow cluster will be invoked and only one model will be saved.

How is this patch tested?

Manual tests

Since TFoS only can run in standalone mode, for now it do not support unitest. But i provide TFoSTest.py to test Manually.

Fix this Issue: #52

[codecov-io]

Codecov Report

Merging #63 into master will decrease coverage by 5.02%.
The diff coverage is 55.75%.

@@            Coverage Diff             @@
##           master      #63      +/-   ##
==========================================
- Coverage   83.06%   78.04%   -5.03%     
==========================================
  Files          23       25       +2     
  Lines        1234     1512     +278     
  Branches        5        5              
==========================================
+ Hits         1025     1180     +155     
- Misses        209      332     +123

Impacted Files	Coverage Δ
python/sparkdl/__init__.py	100% <ø> (ø)	⬆️
python/sparkdl/transformers/utils.py	100% <100%> (ø)	⬆️
...ython/sparkdl/estimators/tf_text_file_estimator.py	42.62% <42.62%> (ø)
python/sparkdl/transformers/tf_text.py	78.26% <78.26%> (ø)
python/sparkdl/param/shared_params.py	81.25% <83.33%> (+1.04%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 328e51e...bbfcb20. Read the comment docs.