HTTP error for new fsspec (#6446)

* Copes with fsspec switching requests -> aiohttp

Fixes #6433

* black

* Add aiohttp to dev envs

continuous_integration/environment-3.6.yaml

@@ -29,6 +29,7 @@ dependencies:
   - s3fs
   - boto3
   - botocore
+  - aiohttp
   - bokeh
   - httpretty
   - chest

continuous_integration/environment-3.7.yaml

@@ -26,6 +26,7 @@ dependencies:
   - blosc
   - boto3
   - botocore
+  - aiohttp
   - bokeh
   - httpretty
   - chest

continuous_integration/environment-3.8-dev.yaml

@@ -27,6 +27,7 @@ dependencies:
   - fsspec>=0.6.0
   - boto3
   - botocore
+  - aiohttp
   - bokeh
   - httpretty
   - chest

continuous_integration/environment-3.8.yaml

@@ -28,6 +28,7 @@ dependencies:
   - botocore
   - bokeh
   - httpretty
+  - aiohttp
   - chest
   - s3fs
   - cloudpickle

dask/bytes/tests/test_http.py

@@ -12,6 +12,10 @@
 
 files = ["a", "b"]
 requests = pytest.importorskip("requests")
+errs = (requests.exceptions.RequestException,)
+if LooseVersion(fsspec.__version__) > "0.7.4":
+    aiohttp = pytest.importorskip("aiohttp")
+    errs = errs + (aiohttp.client_exceptions.ClientResponseError,)
 
 
 @pytest.fixture(scope="module")
@@ -112,7 +116,7 @@ def test_ops_blocksize(dir_server):
 
 def test_errors(dir_server):
     f = open_files("http://localhost:8999/doesnotexist")[0]
-    with pytest.raises(requests.exceptions.RequestException):
+    with pytest.raises(errs):
         with f as f:
             f.read()
     f = open_files("http://nohost/")[0]