Defined function with when and without parenthesis produces incorrect indentation in body

[kcdragon]

Description

When I have a defined, multi-line function and a when with multiple operators without parenthesis, the function body is not indented properly.

Example

Expected

def foo(x) when x + 1 > y do
  []
end

Actual

def foo(x) when x + 1 > y do
                    []
end

Note: This does not happen when x + 1 is wrapped in parenthesis

def foo(x) when (x + 1) > y do
  []
end

Versions

OS: Mac OSX Sierra
Emacs Version: GNU Emacs 25.1.1
elixir-mode: 20170102.942

[kcdragon]

I created a pull request with a failing test since this was recommended in the contributing guide. See #392