0.6.3

Release 0.6.3 of expected lite contains the following.

Fixes

• Fix operator==() for void 'value' type (#51, thanks @Crzyrndm).
• Fix disabling of swap() (#50, thanks @negatratoron).
• Fix cmake config file to use @package_nspace@ (nonstd-lite-project 68).

Changes

• Remove Travis CI configuration and badge (#55, thanks @striezel).
• Do not cancel all jobs in a workflow if one fails. (#54, thanks @striezel).
• Remove gcc 8 and clang 8, 9, 10 from GitHub CI matrix (nonstd-lite-project 69).
• Add compilation and running test for C++20 to GCC and Clang (nonstd-lite-project 64).
• Use toplevel unit_name (nonstd-lite-project 56).