Allowing providerOptions gasLimit and allowUnlimitedContractSize to override defaults

[jjgonecrypto]

By allowing providerOptions.gasLimit be included in .solcover.js, it allows us at Synthetix to avoid these Exceeds block gas limit errors, see : https://travis-ci.org/github/Synthetixio/synthetix/jobs/672297483#L2100-L2148.

Note: I added support for allowUnlimitedContractSize as well cause I was in there and it seemed prudent

[codecov-io]

Codecov Report

Merging #494 into master will not change coverage by %.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #494   +/-   ##
=======================================
  Coverage   99.24%   99.24%           
=======================================
  Files          20       20           
  Lines         790      790           
=======================================
  Hits          784      784           
  Misses          6        6           

Impacted Files	Coverage Δ
lib/api.js	100.00% <100.00%> (ø)

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[cgewecke]

Ah thanks so much @justinjmoses! Makes sense.

[jjgonecrypto]

Thanks Chris. Could you publish 0.7.4 when you get a chance? 🙏

[cgewecke]

@justinjmoses Yes will publish tonight - there's just one other thing I have throw in first :)