Add @ethersproject/solidity, tiny-invariant, jsbi explicit dependencies

[Rubilmax]

Issue

• jsbi@^3.1.4 dependency is used in the package without being defined as an explicit dependency in package.json
• @ethersproject/solidity@^5.0.9 dependency is used in the package without being defined as an explicit dependency in package.json
• tiny-invariant@^1.1.0 dependency is used in the package without being defined as an explicit dependency in package.json

This impacts developers using this package as dependency resolvers (such as npm or yarn) won't automatically install missing dependencies, or will install it with incorrect (and thus perhaps incompatible) versions

Fix

• This PR adds the missing dependencies to package.json without impacting the current state of yarn.lock

[napalmpapalam]

I have this issue too