Better specified urllib3 version

- Avoids urllib3<1.24.3 if it already exists in the system.
- Fixed readme_renderer[md] version

Author: Kronopt

requirements-dev.txt

@@ -1,6 +1,6 @@
 -r requirements-dev27.txt
-pylint==2.1.*               # style
-twine==1.12.*               # pypi tools
-pyOpenSSL==19.0.*           # twine dependency
-readme_renderer[md]==24.*   # command 'twine check'
-wheel==0.32.*               # command 'setup.py sdist bdist_wheel'
+pylint==2.1.*                 # style
+twine==1.12.*                 # pypi tools
+pyOpenSSL==19.0.*             # twine dependency
+readme_renderer[md]==24.0.*   # command 'twine check'
+wheel==0.32.*                 # command 'setup.py sdist bdist_wheel'

requirements.txt

@@ -1,4 +1,4 @@
-beckett==0.8.*      # main functionality
-fcache==0.4.*       # disk-based cache
-requests==2.21.*    # used by beckett (bumped to avoid CVE-2018-18074)
-urllib3==1.24.*     # used by requests (bumped to avoid CVE-2019-11236)
+beckett==0.8.*            # main functionality
+fcache==0.4.*             # disk-based cache
+requests==2.21.*          # used by beckett (bumped to avoid CVE-2018-18074)
+urllib3=>1.24.3,<1.25     # used by requests (bumped to avoid CVE-2019-11236)