requirements: remove some restriction, lock on current versions

requirements.d/development.lock.txt

@@ -1,12 +1,13 @@
-setuptools==40.8.0
-setuptools-scm==3.2.0
-pip==19.0.3
-virtualenv==16.4.3
-pluggy==0.9.0
-tox==3.7.0
-pytest==4.3.1
-pytest-xdist==1.27.0
-pytest-cov==2.6.1
-pytest-benchmark==3.2.2
-Cython==0.29.6
-twine==1.13.0
+setuptools==50.3.0
+setuptools-scm==4.1.2
+pip==20.2.3
+virtualenv==20.0.33
+importlib-metadata==1.7.0
+pluggy==0.13.1
+tox==3.20.0
+pytest==6.1.1
+pytest-xdist==2.1.0
+pytest-cov==2.10.1
+pytest-benchmark==3.2.3
+Cython==0.29.21
+twine==1.15.0

requirements.d/development.txt

@@ -2,12 +2,10 @@ setuptools
 setuptools_scm
 pip
 virtualenv
-# newer cryptography does not build in the jessie vagrant boxes
-cryptography<3.0
 tox
 pytest
 pytest-xdist
 pytest-cov
 pytest-benchmark
-Cython!=0.27
+Cython
 twine