Fix compilation errors with Elixir 0.13.0

lib/geef/commit.ex

@@ -32,7 +32,7 @@ defmodule Geef.Commit do
   def tree!(commit = Object[type: :commit]), do: tree(commit) |> Geef.assert_ok
 
   @spec create(pid, Signature.t, Signature.t, iolist, Oid.t, [Oid.t], [:proplists.property()]) :: {:ok, Oid.t} | {:error, term}
-  def create(repo, author = Signature[], committer = Signature[], message, tree, parents, opts // []) do
+  def create(repo, author = Signature[], committer = Signature[], message, tree, parents, opts \\ []) do
     :geef_commit.create(repo, Signature.to_erl(author), Signature.to_erl(committer), message, tree, parents, opts)
   end
 

lib/geef/index.ex

@@ -1,6 +1,7 @@
+require Record
+
 defmodule Geef.Index do
   use Geef
-  alias Geef.Index
   alias Geef.Index.Entry
 
   defmacrop to_erl(entry) do

lib/geef/iterator.ex

@@ -1,3 +1,5 @@
+require Record
+
 defrecord Geef.Iterator, Record.extract(:geef_iterator, from: "src/geef_records.hrl") do
   alias Geef.Iterator
   alias Geef.Reference

lib/geef/object.ex

@@ -1,3 +1,5 @@
+require Record
+
 defrecord Geef.Object, Record.extract(:geef_object, from: "src/geef_records.hrl") do
 
   @doc false

lib/geef/pkt.ex

@@ -1,3 +1,5 @@
+require Record
+
 defrecord Geef.Request, Record.extract(:geef_request, from: "src/geef_records.hrl")
 
 defmodule Geef.Pkt do

lib/geef/reference.ex

@@ -1,3 +1,5 @@
+require Record
+
 defrecord Geef.Reference, Record.extract(:geef_reference, from: "src/geef_records.hrl") do
   import Geef
   alias Geef.Reference
@@ -8,16 +10,16 @@ defrecord Geef.Reference, Record.extract(:geef_reference, from: "src/geef_record
   defp maybe_ref({:ok, ref}), do: {:ok, Reference.from_erl ref}
   defp maybe_ref(err = {:error, _}), do: err
 
-  def create(repo, name, target, force // :false) do
+  def create(repo, name, target, force \\ :false) do
     :geef_ref.create(repo, name, target, force) |> maybe_ref
   end
-  def create!(repo, name, target, force // :false) do
+  def create!(repo, name, target, force \\ :false) do
     create(repo, name, target, force) |> assert_ok
   end
-  def create_symbolic(repo, name, target, force // :false) do
+  def create_symbolic(repo, name, target, force \\ :false) do
     :geef_ref.create(repo, name, target, force) |> maybe_ref
   end
-  def create_symbolic!(repo, name, target, force // :false) do
+  def create_symbolic!(repo, name, target, force \\ :false) do
     create(repo, name, target, force) |> assert_ok
   end
 
@@ -37,7 +39,7 @@ defrecord Geef.Reference, Record.extract(:geef_reference, from: "src/geef_record
     :geef_ref.shorthand(name)
   end
 
-  def iterator(repo, regexp // :undefined) do
+  def iterator(repo, regexp \\ :undefined) do
     case :geef_ref.iterator(repo, regexp) do
       {:ok, iter} ->
         {:ok, Geef.Iterator.from_erl iter}

lib/geef/signature.ex

@@ -1,3 +1,5 @@
+require Record
+
 defrecord Geef.Signature, Record.extract(:geef_signature, from: "src/geef_records.hrl") do
 
   def now(name, email), do: :geef_sig.now(name, email) |> from_erl

lib/geef/tree.ex

@@ -1,3 +1,5 @@
+require Record
+
 defrecord Geef.TreeEntry, Record.extract(:geef_tree_entry, from: "src/geef_records.hrl") do
   @spec from_erl(term()) :: t
   def from_erl(obj) do