Upgrade all node modules where possible

[area]

The output of npm outdated is now

Package                     Current           Wanted  Latest  Location                            Depended by
openzeppelin-solidity         3.4.2            3.4.2   4.6.0  node_modules/openzeppelin-solidity  colonyNetwork
solidity-coverage      0.8.0-beta.1  0.8.0-rc.test.0  0.7.21  node_modules/solidity-coverage      colonyNetwork

solidity-coverage is a false positive, and openzeppelin-solidity v4 needs solidity v8, so will be done in the solidity branch.

Draft until I've investigated some other stuff, but still interested in feedback. In particular, I've removed request and request-promise (I think) which are deprecated