v0.6.0

• Correctly set .so version [Fixes #52].
  • Warning: All previous releases will be identified as 0.0 by the linker.
• Fix & prevent heap overflow error in example code [#74] [#76] (by @nevun)
• Correctly set OSX dynamic library version [Fixes #75]
• Fix misplaced 0xFF bytes in maps possibly causing memory corruption
• BREAKING: Fix handling & cleanup of failed memory allocation in constructor
  and builder helper functions [Fixes #84]
  • All cbor_new_ and cbor_build_ functions will now explicitly return NULL
    when memory allocation fails
  • It is up to the client to handle such cases
• Globally enforced code style [Fixes #83]
• Fix issue possible memory corruption bug on repeated
  cbor_(byte)string_add_chunk calls with intermittently failing realloc calls
• Fix possibly misaligned reads and writes when endian.h is uses or when
  running on a big-endian machine [Fixes #99, #100]
• Improved CI setup with Travis-native arm64 support
• Docs migrated to Sphinx 2.4 and Python3