premake5 fails

[ivop]

premake5 fails with:

Error: invalid value 'ExtraWarnings' for flags

Removing the offending lines results in:

Error: ~/git/nativejson-benchmark/build/premake5.lua:83: attempt to call a nil value (global 'configuration')

Edit: 5.0.0-beta4 and beta3 fail, but beta2 seems to work.

Edit2: but building still fails, similar failures as #102

[Mysvac]

Change all "configuration" to "configurations".
Change all "flags { "ExtraWarnings" }" to "externalwarnings "Extra"".
Probably