Fix deprecation warnings in Elixir 1.11

[hoyon]

When compiling with Elixir 1.11, you get the following deprecation warnings which I've fixed:

warning: System.stacktrace/0 is deprecated, use __STACKTRACE__ instead
  lib/absinthe/pipeline/batch_resolver.ex:96

warning: System.stacktrace/0 is deprecated, use __STACKTRACE__ instead
  lib/absinthe/subscription/local.ex:73

warning: :crypto.hash/2 defined in application :crypto is used by the current application but the current application does not directly depend on :crypto. To fix this, you must do one of:

  1. If :crypto is part of Erlang/Elixir, you must include it under :extra_applications inside "def application" in your mix.exs

  2. If :crypto is a dependency, make sure it is listed under "def deps" in your mix.exs

  3. In case you don't want to add a requirement to :crypto, you may optionally skip this warning by adding [xref: [exclude: :crypto]] to your "def project" in mix.exs

  lib/absinthe/phase/subscription/subscribe_self.ex:159: Absinthe.Phase.Subscription.SubscribeSelf.get_document_id/3

warning: :httpd_util.hexlist_to_integer/1 defined in application :inets is used by the current application but the current application does not directly depend on :inets. To fix this, you must do one of:

  1. If :inets is part of Erlang/Elixir, you must include it under :extra_applications inside "def application" in your mix.exs

  2. If :inets is a dependency, make sure it is listed under "def deps" in your mix.exs

  3. In case you don't want to add a requirement to :inets, you may optionally skip this warning by adding [xref: [exclude: :httpd_util]] to your "def project" in mix.exs

  lib/absinthe/lexer.ex:282: Absinthe.Lexer.unescape_unicode/5

warning: incompatible types:

    map() !~ atom()

in expression:

    # lib/absinthe/blueprint.ex:215
    module.__absinthe_blueprint__

where "module" was given the type atom() in:

    # lib/absinthe/blueprint.ex:214
    is_atom(module)

where "module" was given the type map() (due to calling var.field) in:

    # lib/absinthe/blueprint.ex:215
    module.__absinthe_blueprint__

HINT: "var.field" (without parentheses) implies "var" is a map() while "var.fun()" (with parentheses) implies "var" is an atom()

Conflict found at
  lib/absinthe/blueprint.ex:215: Absinthe.Blueprint.types_by_name/1

warning: incompatible types:

    map() !~ atom()

in expression:

    # lib/absinthe/blueprint.ex:178
    ext_blueprint.__absinthe_blueprint__

where "ext_blueprint" was given the type atom() in:

    # lib/absinthe/blueprint.ex:177
    is_atom(ext_blueprint)

where "ext_blueprint" was given the type map() (due to calling var.field) in:

    # lib/absinthe/blueprint.ex:178
    ext_blueprint.__absinthe_blueprint__

HINT: "var.field" (without parentheses) implies "var" is a map() while "var.fun()" (with parentheses) implies "var" is an atom()

Conflict found at
  lib/absinthe/blueprint.ex:178: Absinthe.Blueprint.extend_fields/2

warning: incompatible types:

    map() !~ atom()

in expression:

    # lib/absinthe/type.ex:56
    module.functions

where "module" was given the type atom() in:

    # lib/absinthe/type.ex:55
    %module{}

where "module" was given the type map() (due to calling var.field) in:

    # lib/absinthe/type.ex:56
    module.functions

HINT: "var.field" (without parentheses) implies "var" is a map() while "var.fun()" (with parentheses) implies "var" is an atom()

Conflict found at
  lib/absinthe/type.ex:56: Absinthe.Type.expand/1

warning: Mix.Project.compile/1 is deprecated. Use Mix.Task.run("compile", args) instead
  lib/mix/tasks/absinthe.schema.json.ex:81: Mix.Tasks.Absinthe.Schema.Json.run/1

warning: Mix.Project.compile/1 is deprecated. Use Mix.Task.run("compile", args) instead
  lib/mix/tasks/absinthe.schema.sdl.ex:50: Mix.Tasks.Absinthe.Schema.Sdl.run/1

[benwilson512]

Thank you!