Problems for configuring apps with the hypervisor API

[Senyoret1]

Describe the bug
If you try to configure the skysocks-client or the skysocks app using the hypervisor API, the operation will end with an error.

Environment information:

• OS: Linux (Ubuntu 18.04.1)
• Platform: Linux 4.15.0-65-generic x86_64

Steps to Reproduce
Steps to reproduce the behavior:

1. Start some nodes with make integration-run-proxy.
2. Call PUT https://localhost:4200/api/visors/031b80cd5773143a39d940dc0710b93dcccc262a85108018a7a95ab9af734f8055/apps/skysocks-client with {"pk":"024ec47420176680816e0406250e7156465e4531f5b26057c9f6297bb0303558c7"} as arguments, to try to change the public key of the proxy. It will return rpc: can't find method app-visor.SetSocksClientPK.
3. Call PUT https://localhost:4200/api/visors/024ec47420176680816e0406250e7156465e4531f5b26057c9f6297bb0303558c7/apps/skysocks with {"passcode":""} to try to change the password. It will return failed to start skysocks: fork/exec bin/apps/skysocks: no such file or directory

Actual behavior
The operations fail.

Expected behavior
The aperation should finish without problems and the configuration should be updated.

Additional context
The apps appear as running in the manager.

[jdknives]

@Senyoret1 seems to me to be closed by #471 Reopen if there are further issues.