Mismatch between test validator that gets installed and test validator version used as a cache key

[steveluscher]

Our CI script does the following:

1. Look up the latest validator release version
2. Install the validator and cache it if the release version changes

The problem is that the script that does the lookup, presently, finds 1.14.20 but then installs edge (1.17.0).

We need to either:

1. make the lookup fetch the edge version, or
2. make the installer install the version that was yielded in the lookup

The first means that we're always testing against the latest stuff. The second means that we're testing against what the network is running(ish).

Discuss.