Case sensitivity

[szabgab]

It seems the package names in the requirements.txt file
don't always match the case that was used by the author of the package which currently
creates duplicate entries for some of the packages.
The JSON file from PyPI contains the name of the package in the proper case.
When we search for packages we should use a case insensitive search { $strcasecmp: [ , ] }
or maybe we should store a lowercase version of each name, in addition to the official spelling.
URLs in any case should redirect to the canonical spelling.