test: remove poetry test for pre-release version

The test was introduced to test the behavior of a particular pre-release
version of poetry, prior to version 1.0.0 being released.
It has since been released on Dec 12, 2019.

Refs: https://python-poetry.org/blog/announcing-poetry-1-0-0.html
Refs: serverless#395

Signed-off-by: Mike Fiedler <[email protected]>

Author: miketheman

test.js

@@ -1910,17 +1910,3 @@ test(
   },
   { skip: !canUseDocker() }
 );
-
-// From this point on, the version of the poetry is 1.0.0a0
-test('poetry1.0.0a0 py3.6 can package flask with default options', t => {
-  process.chdir('tests/poetry');
-  const path = npm(['pack', '../..']);
-  npm(['i', path]);
-  poetry(['self', 'update', '--preview', '1.0.0a0']);
-  sls(['package']);
-  const zipfiles = listZipFiles('.serverless/sls-py-req-test.zip');
-  t.true(zipfiles.includes(`flask${sep}__init__.py`), 'flask is packaged');
-  t.true(zipfiles.includes(`bottle.py`), 'bottle is packaged');
-  t.true(zipfiles.includes(`boto3${sep}__init__.py`), 'boto3 is packaged');
-  t.end();
-});