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* Remove logic that made relative file paths relative to the path of the
calling code's file. It's now the standard behaviour of relative to the
current working directory. Passing an absolute path is recommended.
* Make comparison of package names case-insensitive to work with
``requirements.txt`` files that use a different case to the canoncial package
name. This can happen with ``pip-compile`` that always outputs lowercase
names.
* Fix 'mismatches' typo
* Only indent mismatch list by 4 spaces in error message