zodburi: v↑ to 3.0.0 for python3

A new version of zodburi has been released [1] that
removes Python2 compatibility shims [2] and is therefore
needed to successfully run 'wendelin.core' tests with python3 [3].

Suggested by @kirr.

[1] https://pypi.org/project/zodburi/3.0.0/
[2] https://github.com/Pylons/zodburi/commit/a00fea755
[3] wendelin.core!35

/reviewed-by @kirr @jerome
/reviewed-on !1745
Status Job ID Name Coverage
  External
passed Cloudooo.UnitTest-Master

00:19:01

failed SlapOS.Eggs.UnitTest-Master.Python2

00:32:24

passed SlapOS.Eggs.UnitTest-Master.Python3

00:24:45

passed SlapOS.Eggs.UnitTest-Master.Python3Next

00:45:57

passed SlapOS.Eggs.UnitTest-TestRunner1.Python2

02:20:25

passed SlapOS.Eggs.UnitTest-TestRunner1.Python3

01:54:49

failed SlapOS.KVM.ResilienceTest-Master

00:30:10

failed SlapOS.SoftwareReleases.IntegrationTest-TestRunner1

12:13:10

passed SlapOS.Theia.ResilienceTest-ForTestRunner1-ERP5

10:46:48

passed SlapOS.Theia.ResilienceTest-ForTestRunner1-Gitlab

19:11:11

failed Zodbtools.UnitTest-Master.ZODB6.Python3

00:00:49