When nodeserver install.sh errors happen, users should not be able to install it.

[jimboca]

User installs nodeserver which has an error, and they see the error popup in Polyglot UI, but still add the nodeserver which fails. I waste time debugging why it's failing, only to see that install failed. I don't think they should be allowed to add a nodeserver when the install fails?

This also relates to #41 where actual errors don't show up in the log unless they enable it in polyglot .env file.

2019-12-2 08:58:10 [polyglot] info: NSChild cloneRepo: Successfully cloned HarmonyHub into NodeServer directory.
2019-12-2 08:58:19 [polyglot] error: NSChild: Install failed - Non-zero exit code: 1
2019-12-2 08:58:19 [polyglot] error: NSChild: HarmonyHub cloneRepo: Error: runInstallProcess: undefined
2019-12-2 08:58:19 [polyglot] error: Error: runInstallProcess: undefined
    at runInstallProcess (/snapshot/polyglot-v2/lib/modules/children.js:45:11)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
2019-12-2 08:58:19 [polyglot] error: NSResponse: Success: false - cloneRepo: Error: runInstallProcess: undefined
2019-12-2 08:58:23 [polyglot] info: HarmonyHub(5): Attempting to install HarmonyHub NodeServer into ISY.
2019-12-2 08:58:24 [polyglot] info: HarmonyHub(5): Installed into ISY sucessfully. Profile uploaded, restart Admin console.
2019-12-2 08:58:24 [polyglot] info: Registered new local NodeServer: HarmonyHub(5)
2019-12-2 08:58:24 [polyglot] info: Waiting 10 seconds before starting HarmonyHub for the first time.
2019-12-2 08:58:34 [polyglot] info: NS: Starting Local NodeServer HarmonyHub profile number 5 :: Version 2.2.7