Umbrella project: error in compilation

### Problem
Umbrella app with compilation error
Project structure:
```
my_project
├── apps
│   ├── my_in_umbrella_project
... ...
├── mix.exs
...
```

### Desired behaviour
Show compilation error in file

### Actual behaviour
In `/mix.exs` :
`[ElixirLS] [E] Build failed for unknown reason. See output log.`

### CocInfo output
```
## Output channel: elixir

Started ElixirLS Fork v0.3.0
Elixir version: "1.10.2 (compiled with Erlang/OTP 21)"
Erlang version: "22"
Compiling with Mix env test

== Compilation error in file lib/my_in_umbrella_project/file.ex ==
** (CompileError) Some compilation error
lib/my_in_umbrella_project/file.ex: (module)
(stdlib 3.12.1) erl_eval.erl:680: :erl_eval.do_apply/6
```