Fix #65: failing test case
Using `Path`s instead of plain strings

Refs #45
Potential fix for #68
Merge pull request #69 from vhbit/bn-zero-fix

Fixes #68: error on linking `bn_is_zero`
Merge pull request #71 from vhbit/path-ization

Using `Path`s instead of plain strings
Fixed incorrect EOF handling in MemBio, added error description

Actually, EOF wasn't handled at all and it caused `mem_bio.read_to_end()` to fail. Which in turn failed all `write_pem` implementations.
Merge pull request #67 from vhbit/membio-eof

Fixed incorrect EOF handling in MemBio, added error description
Merge pull request #66 from jroesch/fix-failing-test

Fix #65: failing test case
Revert "Fix #65: failing test case"
Merge pull request #72 from sfackler/revert-66-fix-failing-test

Revert "Fix #65: failing test case"
Minor documentation fixes