[REF] requirements.txt: Use gevent 1.5.0 version with fixes for >=py3.7.4

The following commit fixes >=py3.7.4 compatibility:
 - https://github.com/gevent/gevent/commit/9d27d269ed01a7e752966caa7a6f85d773780a1a
It was released in stable version gevent==1.5.0 on April 10, 2020:
 - https://pypi.org/project/gevent/1.5.0/

gevent==1.3.4 was released on June 20, 2018
 - https://github.com/gevent/gevent/releases/tag/1.3.4

And python3.7.0 was released June 27, 2018
 - https://www.python.org/downloads/release/python-370/

So, the current pinned version 1.3.4 is not optimized for py3.7

It could be a possible reason to reproduce the following error:
 - https://github.com/odoo/odoo/pull/50861

This change upgrades the pinned version to gevent==1.5.0
in order to get an optimized version for py3.7

Bump version to greenlet==0.4.14 for py3.7 since that it is the
version defined in the sha of release of gevent==1.5.0
 - https://github.com/gevent/gevent/commit/a1a72cb9
 - https://github.com/gevent/gevent/blob/a1a72cb9/setup.py#L188



closes odoo/odoo#56167

Signed-off-by: Christophe Monniez (moc) <moc@odoo.com>

requirements.txt

@@ -4,10 +4,9 @@ docutils==0.12
 ebaysdk==2.1.5
 feedparser==5.2.1
 gevent==1.1.2 ; sys_platform != 'win32' and python_version < '3.7'
-gevent==1.3.4 ; sys_platform != 'win32' and python_version >= '3.7'
-gevent==1.4.0 ; sys_platform == 'win32' and python_version >= '3.7'
+gevent==1.5.0 ; python_version >= '3.7'
 greenlet==0.4.10 ; python_version < '3.7'
-greenlet==0.4.13 ; python_version >= '3.7'
+greenlet==0.4.14 ; python_version >= '3.7'
 html2text==2016.9.19
 Jinja2==2.10.1
 lxml==3.7.1 ; sys_platform != 'win32' and python_version < '3.7'