Specify explicitly the versions

Author: andrivet

requirements-dev.txt

@@ -1,13 +1,13 @@
 -r requirements.txt
-pytest
-tox
-flake8
-isort
-docutils
-check-manifest
-readme-renderer
-pygments
-sphinx
-sphinx_rtd_theme
-coverage
+pytest==5.4.1
+tox==3.14.6
+flake8==3.7.9
+isort==4.3.21
+docutils==0.16
+check-manifest==0.41
+readme-renderer==25.0
+pygments==2.6.1
+sphinx==3.0.0
+sphinx_rtd_theme==0.4.3
+coverage==5.0.4