Run separate CI task for all tests with external (apt-get) dependencies

[gnidan]

Issue

Travis is slow and getting slower now that both solc and vyper have to get installed.

Steps to Reproduce

1. https://travis-ci.org/trufflesuite/truffle
2. Options -> Trigger Build -> etc.
3. Wait longer than an amount of time for which it is reasonable to have patience

Expected Behavior

The two main CI jobs (Packages & Integrations) should not run any tests that rely on any packages installed by apt-get.

A separate job should run for specifically these tests. (unknown requirement: should this job be marked as "allowed failure"?)

Background

There are at least two places where CI environment changes how or which tests are run:

• The external compile tests use the jq utility, so these only run if the CI environment variable is true.

• A bunch of tests are marked [ @geth ] (e.g.), which gets indicated to mocha by way of the "test filter" option.*

*This approach is annoying because it means the main CI script for running "all the tests" consumes this CLI flag (-k I think but I'm too lazy to look it up). So you can't use -k locally, effectively at all, if you just want to do yarn test -k ...some filter... in the root.

For this issue, it may be worth thinking of a more explicit strategy for how CI manages collections of tests. Or not. Alternate strategy: hack it in and get tests faster by any means necessary.

Environment

Travis-CI

[eggplantzzz]

Random Note: having the keyword 'native' in the string that heads a describe or it block (in the tests) causes that chunk of tests to be excluded while running the tests in truffle-compile due to the testing script found in that package.

[Mordax]

Regarding the tests on Vyper failing issue, maybe Vyper can be checked separately to Solidity? Like having two test bundles that depend on a flag to run one at a time when needed, so that any Vyper issues are separated and easier to tackle and build more test support?