Add RegisterInvariants to Configuration

[likhita-809]

Closes: #223

An Invariant is a function that checks for a particular invariant within a module. These functions are useful to detect bugs early on and act upon them to limit their potential consequences (e.g. by halting the chain). If the invariant has been broken, it should return an error containing a descriptive message about what happened and a boolean indicating whether the invariant has been broken.

[codecov]

Codecov Report

Merging #273 (d706766) into master (1b7c80e) will decrease coverage by 0.42%.
The diff coverage is 48.45%.

@@            Coverage Diff             @@
##           master     #273      +/-   ##
==========================================
- Coverage   62.17%   61.74%   -0.43%     
==========================================
  Files          47       48       +1     
  Lines        3003     3100      +97     
==========================================
+ Hits         1867     1914      +47     
- Misses        914      947      +33     
- Partials      222      239      +17     

[blushi]

groupTotalWeightInvariant implementation is wrong

[blushi]

almost there! just a small fix and nit

[amaury1093]

I had a look at both invariants, and their tests, it lgtm. Thanks @likhita-809 and @blushi!

[amaury1093]

One invariant I'm thinking is: the Tally on a proposal should be equal to the sum of all weigthed votes. @blushi Do you think that's useful? (If yes, we can definitely add that in another PR).

[blushi]

One invariant I'm thinking is: the Tally on a proposal should be equal to the sum of all weigthed votes. @blushi Do you think that's useful? (If yes, we can definitely add that in another PR).

Indeed, created a new issue to tackle this #326

[blushi]

pre-approving, pending small change requests

[blushi]

Thanks @likhita-809!