Viper won't override nested config with cli flags

[y0sher]

Using viper we load config from a toml file. we wan't the default config to be loaded, then overridden by a config file if exists, then overridden by the cli flags.

viper claim this to work after spf13/viper#195

couldn't get it working for us so I had to add some patch in #238 .

How to fix ?

• Use normal viper methods to load cli flags after config
• write tests to show that the flow described above works.

[y0sher]

we have an ugly fix for it, though viper claimed to fix the problem and I saw some more elegant fixes to it on github.