[whitelist-weighted-json] New strategy

[thierbig]

Adds a new strategy to circumvent the max limit of the whitelist-weighted strategy
Changes proposed in this pull request:

• Add a new strategy called whitelist-weighted-json strategy. The strategy uses a hosted json file that will allow bigger whitelists to be sent

[ChaituVR]

Hi @thierbig Make sure the tests are passing, try running yarn test --strategy=whitelist-weighted-json in your local, Also I'd suggest you to use api-v2 strategy and format your JSON accordingly

[thierbig]

Hi @ChaituVR. All the tests are now passing. The api-v2 strategy has been giving me trouble and I think the strategy I'm introducing will be easy to use for newcomers to the platform like myself.