keep an eye on python web3 build errors in CI

[ivoysey]

this may go away on its own, but as of https://app.travis-ci.com/github/mcoblenz/Obsidian/builds/247118840 we see

ERROR: eth-keys 0.3.4 has requirement eth-typing<3.0.0,>=2.2.1, but you'll have eth-typing 3.0.0 which is incompatible.

ERROR: eth-keys 0.3.4 has requirement eth-utils<2.0.0,>=1.8.2, but you'll have eth-utils 2.0.0 which is incompatible.

ERROR: rlp 2.0.1 has requirement eth-utils<2,>=1.0.2, but you'll have eth-utils 2.0.0 which is incompatible.

ERROR: eth-keyfile 0.5.1 has requirement eth-utils<2.0.0,>=1.0.0-beta.1, but you'll have eth-utils 2.0.0 which is incompatible.

ERROR: eth-account 0.5.7 has requirement eth-abi<3,>=2.0.0b7, but you'll have eth-abi 3.0.0 which is incompatible.

ERROR: eth-account 0.5.7 has requirement eth-utils<2,>=1.3.0, but you'll have eth-utils 2.0.0 which is incompatible.

ERROR: web3 5.28.0 has requirement eth-abi<3.0.0,>=2.0.0b6, but you'll have eth-abi 3.0.0 which is incompatible.

ERROR: web3 5.28.0 has requirement eth-typing<3.0.0,>=2.0.0, but you'll have eth-typing 3.0.0 which is incompatible.

ERROR: web3 5.28.0 has requirement eth-utils<2.0.0,>=1.9.5, but you'll have eth-utils 2.0.0 which is incompatible.

around Line 359 of the build output. it still runs the tests to completion. maybe pip itself ought to get updated in travis.yml?