Add crypto into the required applications

As suggested by @prof3ta.

src/cowboy.app.src

@@ -20,7 +20,8 @@
 	{applications, [
 		kernel,
 		stdlib,
-		ranch
+		ranch,
+		crypto
 	]},
 	{mod, {cowboy_app, []}},
 	{env, []}

src/cowboy_websocket.erl

@@ -13,10 +13,6 @@
 %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 %% @doc WebSocket protocol implementation.
-%%
-%% When using websockets, make sure that the crypto application is
-%% included in your release. If you are not using releases then there
-%% is no need for concern as crypto is already included.
 -module(cowboy_websocket).
 
 %% API.

test/http_SUITE.erl

@@ -128,6 +128,7 @@ groups() ->
 
 init_per_suite(Config) ->
 	application:start(inets),
+	application:start(crypto),
 	application:start(ranch),
 	application:start(cowboy),
 	Config.
@@ -135,6 +136,7 @@ init_per_suite(Config) ->
 end_per_suite(_Config) ->
 	application:stop(cowboy),
 	application:stop(ranch),
+	application:stop(crypto),
 	application:stop(inets),
 	ok.
 
@@ -159,7 +161,6 @@ init_per_group(https, Config) ->
 		{password, "cowboy"}
 	],
 	Config1 = init_static_dir(Config),
-	application:start(crypto),
 	application:start(public_key),
 	application:start(ssl),
 	{ok, _} = cowboy:start_https(https, 100, Opts ++ [{port, Port}], [
@@ -199,7 +200,6 @@ end_per_group(https, Config) ->
 	cowboy:stop_listener(https),
 	application:stop(ssl),
 	application:stop(public_key),
-	application:stop(crypto),
 	end_static_dir(Config),
 	ok;
 end_per_group(http, Config) ->

test/ws_SUITE.erl

@@ -33,6 +33,7 @@ groups() ->
 
 init_per_suite(Config) ->
 	application:start(inets),
+	application:start(crypto),
 	application:start(ranch),
 	application:start(cowboy),
 	Config.
@@ -40,6 +41,7 @@ init_per_suite(Config) ->
 end_per_suite(_Config) ->
 	application:stop(cowboy),
 	application:stop(ranch),
+	application:stop(crypto),
 	application:stop(inets),
 	ok.