TST: shift_across_dst failures
https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=48611&view=logs&j=4b4d380c-92b5-58cf-5b80-2c6c9b1d5805&t=8eab1181-1335-58ed-7ed5-a271d9d86005

we want to see if this is a bug / add a test case

```
2020-11-26T11:02:32.6835667Z ##[section]Starting: Test
2020-11-26T11:02:32.6968461Z ==============================================================================
2020-11-26T11:02:32.6969827Z Task         : Bash
2020-11-26T11:02:32.6970534Z Description  : Run a Bash script on macOS, Linux, or Windows
2020-11-26T11:02:32.6971261Z Version      : 3.177.2
2020-11-26T11:02:32.6971826Z Author       : Microsoft Corporation
2020-11-26T11:02:32.6972383Z Help         : https://docs.microsoft.com/azure/devops/pipelines/tasks/utility/bash
2020-11-26T11:02:32.6973012Z ==============================================================================
2020-11-26T11:02:32.9619865Z Generating script.
2020-11-26T11:02:32.9824762Z [command]"C:\Program Files\Git\bin\bash.exe" --noprofile --norc -c pwd
2020-11-26T11:02:33.0802003Z /d/a/_temp
2020-11-26T11:02:33.0846216Z 
2020-11-26T11:02:33.0876225Z ========================== Starting Command Output ===========================
2020-11-26T11:02:33.0885510Z [command]"C:\Program Files\Git\bin\bash.exe" --noprofile --norc /d/a/_temp/d7f72ca5-7653-4d39-b14e-c4a3a640dc91.sh
2020-11-26T11:02:33.7933378Z pytest -m "not slow and not network" -n auto --dist=loadfile -s --strict --durations=30 --junitxml=test-data.xml pandas --ignore=pandas/tests/window/ --ignore=pandas/tests/plotting/
2020-11-26T11:03:46.1230792Z ##[warning]Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it will stop working
2020-11-26T11:03:46.1290301Z ##[warning]Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it will stop working
2020-11-26T11:03:46.1292192Z ##[warning]Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it will stop working
2020-11-26T11:03:46.1293979Z ##[warning]Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it will stop working
2020-11-26T11:03:46.1295207Z ============================= test session starts =============================
2020-11-26T11:03:46.1295831Z platform win32 -- Python 3.7.9, pytest-6.1.1, py-1.9.0, pluggy-0.13.1
2020-11-26T11:03:46.1296368Z rootdir: D:\a\1\s, configfile: setup.cfg, testpaths: pandas
2020-11-26T11:03:46.1296847Z plugins: hypothesis-5.41.3, azurepipelines-0.8.0, forked-1.3.0, xdist-2.1.0
2020-11-26T11:03:46.1297375Z gw0 I / gw1 I
2020-11-26T11:03:46.1297683Z gw0 [98481] / gw1 [98481]
2020-11-26T11:03:46.1297932Z 
2020-11-26T11:19:01.9006050Z Result Attachments will be stored in LogStore
2020-11-26T11:19:01.9506376Z Run Attachments will be stored in LogStore
2020-11-26T11:19:03.1155850Z ##[error]1 test(s) failed, 98481 test(s) collected.
2020-11-26T11:19:03.1158156Z Skipping uploading of coverage data.
2020-11-26T11:19:03.1158771Z 
2020-11-26T11:19:03.1159206Z ================================== FAILURES ===================================
2020-11-26T11:19:03.1159714Z ____________________________ test_shift_across_dst ____________________________
2020-11-26T11:19:03.1160220Z [gw1] win32 -- Python 3.7.9 C:\Miniconda\envs\pandas-dev\python.exe
2020-11-26T11:19:03.1160827Z 
2020-11-26T11:19:03.1161077Z     @given(gen_yqm_offset)
2020-11-26T11:19:03.1161361Z >   def test_shift_across_dst(offset):
2020-11-26T11:19:03.1161564Z 
2020-11-26T11:19:03.1161828Z pandas\tests\tseries\offsets\test_offsets_properties.py:107: 
2020-11-26T11:19:03.1162225Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
2020-11-26T11:19:03.1163012Z C:\Miniconda\envs\pandas-dev\lib\site-packages\hypothesis\core.py:661: in execute_once
2020-11-26T11:19:03.1164457Z     % (test.__name__, text_repr[0])
2020-11-26T11:19:03.1164917Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
2020-11-26T11:19:03.1165284Z 
2020-11-26T11:19:03.1165669Z self = <hypothesis.core.StateForActualGivenExecution object at 0x000001EC3C0E6D08>
2020-11-26T11:19:03.1166349Z message = 'Hypothesis test_shift_across_dst(offset=<-4 * BYearEnds: month=1>) produces unreliable results: Falsified on the first call but did not on a subsequent one'
2020-11-26T11:19:03.1168377Z 
2020-11-26T11:19:03.1168728Z     def __flaky(self, message):
2020-11-26T11:19:03.1169153Z         if len(self.falsifying_examples) <= 1:
2020-11-26T11:19:03.1169544Z >           raise Flaky(message)
2020-11-26T11:19:03.1170217Z E           hypothesis.errors.Flaky: Hypothesis test_shift_across_dst(offset=<-4 * BYearEnds: month=1>) produces unreliable results: Falsified on the first call but did not on a subsequent one
2020-11-26T11:19:03.1170780Z 
2020-11-26T11:19:03.1171182Z C:\Miniconda\envs\pandas-dev\lib\site-packages\hypothesis\core.py:866: Flaky
2020-11-26T11:19:03.1171722Z --------------------------------- Hypothesis ----------------------------------
2020-11-26T11:19:03.1172169Z Falsifying example: test_shift_across_dst(
2020-11-26T11:19:03.1172581Z     offset=<-4 * BYearEnds: month=1>,
2020-11-26T11:19:03.1172904Z )
2020-11-26T11:19:03.1173635Z Unreliable test timings! On an initial run, this test took 638.78ms, which exceeded the deadline of 500.00ms, but on a subsequent run it took 1.55 ms, which did not. If you expect this sort of variability in your test timings, consider turning deadlines off for this test by setting deadline=None.
2020-11-26T11:19:03.1174495Z 
2020-11-26T11:19:03.1174995Z You can reproduce this example by temporarily adding @reproduce_failure('5.41.3', b'AAsAAQQA') as a decorator on your test case
2020-11-26T11:19:03.1175561Z ============================== warnings summary ===============================
2020-11-26T11:19:03.1176092Z C:\Miniconda\envs\pandas-dev\lib\site-packages\matplotlib\__init__.py:107
2020-11-26T11:19:03.1176625Z C:\Miniconda\envs\pandas-dev\lib\site-packages\matplotlib\__init__.py:107
```