adds Firebase communication stump

- Firebase connection via Pigeon library
- sends bump to a single token at the moment
- encrypted test is sent as notification message

lib/bump/database.ex

@@ -0,0 +1,62 @@
+defmodule Bump.Database do
+  alias Bump.Repo
+  alias Bump.Messages.Message
+  import Ecto.Query
+
+  def pop(sender) do
+    query = from m in "messages",
+            where: m.sender == ^sender,
+            order_by: [desc: m.timestamp],
+            limit: 1,
+            select: %{id: m.id, data: m.data, timestamp: m.timestamp}
+
+    res = Repo.one(query)
+
+    if not is_nil(res) do
+      Repo.delete_all(from m in "messages", where: m.id == ^res.id)
+    %{data: res.data, timestamp: res.timestamp}
+    else
+    %{} 
+    end
+
+  end
+
+  def peek(sender) do
+    query = from m in "messages",
+            where: m.sender == ^sender,
+            order_by: [desc: m.timestamp],
+            limit: 1,
+            select: %{data: m.data, timestamp: m.timestamp}
+    Repo.one(query)
+  end
+
+  def list(sender, minutes) do
+
+    ago = DateTime.utc_now 
+          |> Timex.shift(minutes: -minutes) 
+          |> DateTime.truncate(:second)
+
+    query = from m in "messages",
+            where: m.sender == ^sender and
+            m.timestamp >= ^ago,
+            select: %{data: m.data, timestamp: m.timestamp}
+
+    Repo.all(query)
+  end
+
+  def clear(sender) do
+    query = from m in "messages",
+            where: m.sender == ^sender
+
+    Repo.delete_all(query)
+  end
+
+  def push(sender, message) do
+    time = DateTime.utc_now |> DateTime.truncate(:second)
+
+    Repo.insert(%Message{sender: sender, data: message, timestamp: time})
+
+  end
+
+
+end