Fix tests broken by pytest-asyncio breaking-changes (#754)

Update `tests` not to declare `loop` argument

Author: habara-k

tests/async_api/test_get_message_content.py

@@ -20,7 +20,7 @@
 from linebot.aiohttp_async_http_client import AiohttpAsyncHttpClient
 
 
-async def test_get(aiohttp_client, loop):
+async def test_get(aiohttp_client):
     msg = ''.join('Hello, world' for i in range(1000))
 
     async def hello(request):

tests/async_api/test_get_profile.py

@@ -20,7 +20,7 @@
 from linebot.aiohttp_async_http_client import AiohttpAsyncHttpClient
 
 
-async def test_async_profile(aiohttp_client, loop):
+async def test_async_profile(aiohttp_client):
     expect = {
         'displayName': 'test',
         'userId': 'test',

tests/test_aiohttp_async_http_client.py

@@ -17,7 +17,7 @@
 from linebot.aiohttp_async_http_client import AiohttpAsyncHttpClient
 
 
-async def test_get(aiohttp_client, loop):
+async def test_get(aiohttp_client):
     async def hello(request):
         return web.Response(text='Hello, world')
 
@@ -31,7 +31,7 @@ async def hello(request):
     assert 'Hello, world' in text
 
 
-async def test_get_json(aiohttp_client, loop):
+async def test_get_json(aiohttp_client):
     async def hello(request):
         return web.json_response({'test': 'Hello, world'})
 
@@ -44,7 +44,7 @@ async def hello(request):
     assert 'Hello, world' == json['test']
 
 
-async def test_get_iter(aiohttp_client, loop):
+async def test_get_iter(aiohttp_client):
     async def hello(request):
         return web.Response(text='Hello, world')
 
@@ -61,7 +61,7 @@ async def hello(request):
     assert 'Hello, world' in buffer
 
 
-async def test_post(aiohttp_client, loop):
+async def test_post(aiohttp_client):
     async def hello(request):
         return web.Response(text='Hello, world')
 
@@ -75,7 +75,7 @@ async def hello(request):
     assert 'Hello, world' in text
 
 
-async def test_delete(aiohttp_client, loop):
+async def test_delete(aiohttp_client):
     async def hello(request):
         return web.Response(text='Hello, world')
 
@@ -89,7 +89,7 @@ async def hello(request):
     assert 'Hello, world' in text
 
 
-async def test_put(aiohttp_client, loop):
+async def test_put(aiohttp_client):
     async def hello(request):
         return web.Response(text='Hello, world')