repin some test dependencies

test_requirements.txt

@@ -3,16 +3,17 @@ pytest-cov
 pytest-cover
 pytest-pep8
 pytest-xdist
-pytest-mock
-mock
-coverage
-moto
+pytest-mock>=1.5.0,<3.0.0
+mock>=1.0.1,<5.0.0
+coverage>=3.7.1,<6.0.0
+moto==3.0.7
 # these overlap with requirements specified in doc_requirements. As long as they are needed, these specifications must be kept in sync
 # TODO: see if we can avoid duplicating these requirements - this will involved surveying CI
-pep8
-flake8
-pylint
-jinja2>=2.7.3
-numpydoc
-jupyter
-markupsafe
+pep8==1.7.0,<2.0.0
+flake8>=1.5.0,<4.0.0
+pylint>=1.5.4,<3.0.0
+jinja2>=2.7.3,<2.12.0
+numpydoc>=0.6.0,<1.0.0
+jupyter>=1.0.0,<2.0.0
+markupsafe==2.0.1
+pywinpty==2.0.2; python_version <= '3.6' and sys_platform == 'win32'