test(pytest): set python_path directly in pytest.ini

Previously the python_path used by pytest
was only defined in tox.ini that could be
a problem when pytest was run without tox.

This commit setup python_path directly in
the pytest configuration file.

pytest.ini

@@ -1,6 +1,7 @@
 [pytest]
 norecursedirs = .git .* *.egg* old docs dist build
 addopts = -p no:warnings
+python_paths = package/
 filterwarnings =
     # python3.4 raises this when importing setuptools
     ignore:The value of convert_charrefs will become True in 3.5.*:DeprecationWarning

tox.ini

@@ -6,13 +6,12 @@ skipsdist = True
 [testenv:pytest]
 basepython = python3
 skip_install = true
-setenv =
-    PYTHONPATH = package/
 deps =
-    pytest
-    pytest-cov
-    botocore
-    boto3
+    pytest==6.1.1
+    pytest-cov==2.10.1
+    pytest-pythonpath==0.7.3
+    botocore==1.18.16
+    boto3==1.15.16
     moto==1.3.14
 commands =
     coverage run -m pytest tests/unit --disable-pytest-warnings --cov package 
@@ -21,47 +20,46 @@ commands =
 basepython = python3
 skip_install = true
 deps =
-    black>=19.3b0
+    black==20.8b1
 commands =
     black package/ --line-length 79 --check
 
 [testenv:flake8]
 basepython = python3
 skip_install = true
 deps =
-    flake8
-    flake8-colors
-    flake8-docstrings>=0.2.7
-    # remove when https://gitlab.com/pycqa/flake8-docstrings/issues/36 is fixed
-    pydocstyle<4
-    flake8-import-order>=0.9
-    flake8-typing-imports>=1.1
-    pep8-naming
+    flake8==3.8.4
+    flake8-colors==0.1.6
+    flake8-docstrings==1.5.0
+    pydocstyle==5.1.1
+    flake8-import-order==0.18.1
+    flake8-typing-imports==1.10.0
+    pep8-naming==0.11.1
 commands =
     flake8 package/
 
 [testenv:pylint]
 basepython = python3
 skip_install = true
 deps =
-    pyflakes
-    pylint==2.4.4
+    pyflakes==2.2.0
+    pylint==2.6.0
 commands =
     pylint package/ --rcfile=tests/sanity/.pylintrc
 
 [testenv:bandit]
 basepython = python3
 skip_install = true
 deps =
-    bandit
+    bandit==1.6.2
 commands =
     bandit -r package/ -c tests/sanity/.bandit.yml
 
 [testenv:mypy]
 basepython = python3
 skip_install = true
 deps =
-    mypy
+    mypy==0.790
 commands =
     mypy --ignore-missing-imports package/