adds senders to database and firebase connect

- senders, which now have a firebase token
  are added as their own table in the database
- firebase token api call added, which allows
  a user to connect a sender id to a firebase token
- firebase library not yet connected to the saved
  firebase tokens

lib/bump/database.ex

@@ -1,6 +1,7 @@
 defmodule Bump.Database do
   alias Bump.Repo
   alias Bump.Messages.Message
+  alias Bump.Senders.Sender
   import Ecto.Query
 
   def pop(sender) do
@@ -58,5 +59,8 @@ defmodule Bump.Database do
 
   end
 
+  def addSender(sender, %{"firebase" => firebase}) do
+    Repo.insert(%Sender{sender: sender, firebase_token: firebase})
+  end
 
 end

lib/bump/messages.ex

@@ -3,7 +3,7 @@ defmodule Bump.Messages do
   alias Bump.Firebase
 
   def pop(sender) do
-       Database.pop(sender)
+    Database.pop(sender)
   end
 
   def peek(sender) do

lib/bump/senders.ex

@@ -0,0 +1,12 @@
+defmodule Bump.Senders do
+  alias Bump.Database
+
+  def firebase(sender, firebase) do
+    Database.addSender(sender, %{"firebase" => firebase})
+  end
+
+  def peek(sender) do
+    Database.peek(sender)
+  end
+
+end

lib/bump/senders/sender.ex

@@ -0,0 +1,18 @@
+defmodule Bump.Senders.Sender do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  schema "senders" do
+    field :sender, :string
+    field :firebase_token, :string, default: ""
+    timestamps()
+  end
+
+  def changeset(sender, params) do
+   sender 
+    |> cast(params, [:sender, :firebase_token])
+  end
+end
+
+
+