Use lazy_static about tox

[kurnevsky]

I'd prefer to use consts. In this case we can change time type from Instant to SystemTime and in tests set this time manually to the past like it was done in onion. It's simpler than this magic with lazy static. And one more benefit - SystemTime is more precise than Instant:

Note, however, that instants are not guaranteed to be steady. In other words, each tick of the underlying clock may not be the same length (e.g. some seconds may be longer than others). An instant may jump forwards or experience time dilation (slow down or speed up), but it will never go backwards.

[kurnevsky]

One thing that came to my mind - we can define different constants for tests and real code, using cfg attribute:

#[cfg(not(test))]
const MY_CONST: u32 = 1;
#[cfg(test)]
const MY_CONST: u32 = 123;

[kpp]

Do we need this issue anymore?

[kurnevsky]

It depends. We still have these values as variables in config, and it's better to refactor it and change them to consts.