drop unused Tox (#1242)

tox.ini

@@ -1,54 +0,0 @@
-# this file is *not* meant to cover or endorse the use of tox or pytest or testing in general,
-#
-#  It's meant to show the use of:
-#
-#  - check-manifest
-#     confirm items checked into vcs are in your segdist
-#  - python setup.py check
-#     confirm required package meta-data in setup.py
-#  - readme_renderer (when using a ReStructuredText README)
-#     confirms your long_description will render correctly on PyPI.
-#
-#  and also to help confirm pull requests to this project.
-
-[tox]
-envlist = py{35,36,37,38}
-
-# DROP, it is duplication of setup.cfg
-# [pytest]
-# log_cli = 0
-# log_cli_level = CRITICAL
-# log_cli_format = %(message)s
-# log_file = pytest.log
-# log_file_level = DEBUG
-# log_file_format = %(asctime)s [%(levelname)8s] %(message)s (%(filename)s:%(lineno)s)
-# log_file_date_format=%Y-%m-%d %H:%M:%S
-
-[testenv]
-basepython =
-    py35: python3.5
-    py36: python3.6
-    py37: python3.7
-    py38: python3.8
-deps =
-    # this is derived requirements
-    -r requirements.txt
-    -r ./tests/requirements.txt
-commands =
-    pip list
-    check-manifest
-    python setup.py check --metadata --strict
-    coverage run --source pytorch_lightning -m py.test pytorch_lightning tests -v --doctest-modules
-    coverage report
-    python setup.py sdist
-    twine check dist/*
-
-# DROP, it is duplication of setup.cfg
-# [flake8]
-# exclude = .tox,*.egg,build,temp,examples/*
-# select = E,W,F
-# doctests = True
-# verbose = 2
-# https://pep8.readthedocs.io/en/latest/intro.html#error-codes
-# format = pylint
-# max-line-length = 100