Updated dependencies and deleted the unsecure ones

requirements/dev.txt

@@ -1,12 +1,10 @@
 -r prod.txt
 
-pip==19.0.3
-bumpversion==0.5.3
-wheel==0.33.1
-watchdog==0.9.0
-flake8==3.7.7
-tox==3.8.4
-coverage==4.5.3
-Sphinx==2.0.0
-cryptography==2.6.1
-PyYAML==5.1
+bumpversion==0.6.0
+watchdog==0.10.3
+flake8==3.8.3
+tox==3.19.0
+coverage==5.2.1
+Sphinx==3.2.0
+cryptography==3.0
+PyYAML==5.3.1

requirements/prod.txt

@@ -1,2 +1,2 @@
 colorthief==0.2.1
-Pillow==6.0.0
+Pillow==7.2.0