Fix some type

lib/koans/08_pattern_matching.ex

@@ -16,7 +16,7 @@ defmodule PatternMatching do
     assert a == ___
   end
 
-  koan "A variable can be pinned to be prevent it from being rebound" do
+  koan "A variable can be pinned to prevent it from being rebounded" do
     a = 1
     assert_raise MatchError, fn() ->
       ^a = ___

lib/koans/09_functions.ex

@@ -35,7 +35,7 @@ defmodule Functions do
   def sum_up(_thing), do: :single_thing
 
   koan "Functions can have guard expressions" do
-    assert sum_up([1 ,2 ,3]) == ___
+    assert sum_up([1, 2, 3]) == ___
     assert sum_up(1) == ___
   end
 

lib/koans/11_processes.ex

@@ -81,8 +81,8 @@ defmodule Processes do
   koan "Processes can be used to hold state" do
     initial_state = "foo"
     pid = spawn(fn ->
-            state(initial_state)
-          end)
+      state(initial_state)
+    end)
 
     send pid, {self, :get}
     assert_receive ___