v0.7.1: upgrade pyaxis to version 0.3.1
v0.7.0:
    - upgrade pyaxis to version 0.3.0
    - documentation updates
v0.6.2:
    - change subprocess calls, locking the execution until subprocess ends.
    - fix error raised deleting SQL Loader output files.
    - refactor integration tests for oracle class.
v0.6.1: updated SQLAlchemy in requirements.txt to fix moderate security issues.
v0.6.0: added support for xlsx extraction.
v0.5.0: added limited support for Postgresql database.
v0.4.5: fixed dependencies in setup.py.
v0.4.4: added support for massively reading Px files from a given directory.
v0.4.3: added different encodings for csv and px in extractor px.
v0.4.2: added support for parametrized columns load in bulk insert and upsert.
