Log Message:
elixir: Update to 1.10.4

## v1.10.4 (2020-07-04)

### 1. Bug fixes

#### Elixir

  * [Kernel] Fix a bug where custom types were printed as built-in types
  * [Kernel] Don't add compile-time dependency on `defdelegate`
  * [Kernel] Add line numbers to warnings on deprecated imports
  * [Kernel] Report the correct line number when raising inside a macro
  * [Task] Include callers in translated Logger metadata for Task
  * [Task] Fix Task PID and caller in Task Supervisor reports

#### ExUnit

  * [ExUnit.Formatter] Avoid crashes when diffing guards when the pattern does \ 
not match
  * [ExUnit.Formatter] Also blame exceptions that come from linked and trapped exits

#### IEx

  * [IEx.Helpers] Do not crash when printing a type that cannot be code formatted

####  Mix

  * [mix app.start] Fix reading `.app` file located in archives (`.ez` files)
  * [mix local.hex] Provide more guidance when Hex can't be installed
  * [mix release] Properly encode config in releases