Using flint with pyspark on yarn

Hi,
I'm trying to use flint submitting a pyspark job on yarn.

```
>> ./bin/pyspark --master yarn --deploy-mode client --jars /opt/flint-assembly-0.2.0-SNAPSHOT.jar --py-files /opt/flint-assembly-0.2.0-SNAPSHOT.jar`
[..]
SparkSession available as 'spark'.
>>> import ts.flint
Traceback (most recent call last):
File "", line 1, in
ModuleNotFoundError: No module named 'ts'
>>> import sys
>>> sys.path
['', '/tmp/spark-1d453f8f-379a-4f22-a7e4-cabe9dad15c5/userFiles-0b6ed883-15b1-4893-acb8-977f74b09913/flint-assembly-0.2.0-SNAPSHOT.jar', '/tmp/spark-1d453f8f-379a-4f22-a7e4-cabe9dad15c5/userFiles-0b6ed883-15b1-4893-acb8-977f74b09913', '/usr/hdp/2.6.1.0-129/spark2/python/lib/py4j-0.10.4-src.zip', '/usr/hdp/2.6.1.0-129/spark2/python', '/usr/hdp/2.6.1.0-129/spark2', '/opt/miniconda3/envs/lhd_spark/lib/python36.zip', '/opt/miniconda3/envs/lhd_spark/lib/python3.6', '/opt/miniconda3/envs/lhd_spark/lib/python3.6/lib-dynload', '/opt/miniconda3/envs/lhd_spark/lib/python3.6/site-packages', '/opt/miniconda3/envs/lhd_spark/lib/python3.6/site-packages/setuptools-27.2.0-py3.6.egg']

```

Using same approach on master local works properly while on yarn seems to refer to invalid path and the import fails.

I was able to use the library following [this similar topic](https://stackoverflow.com/questions/36397136/importing-pyspark-packages ) extracting python code from the jar and copying it in my working directory.

Is that ok or there is a better way to proceed?