Bring back tempita to u-c

Tempita pip package is broken and not maintained since 2013[1].
Because it uses 'use_2to3' command in all versions[2] which is
deprecated since setuptools>58[3], it is not impossible to build this
package from source.
The only installation method that still works is wheel, but PyPI
does not store wheels for development versions(0.5.3dev in our case).

So if user runs `pip install` with '--pre' attribute and tempita is not
constrained to 0.5.2, then pip attempts to install 0.5.3dev that does
not have wheel stored in PyPI and the install command fails because
building this package from source does not work.

Openstack-Ansbile project is affected by this issue.

[1] https://pypi.org/project/Tempita/#history
[2] https://github.com/agramfort/tempita/blob/master/setup.py#L53
[3] https://setuptools.pypa.io/en/latest/history.html#v58-0-0

Change-Id: Id01c10796bb307c2696214dc9b3217242a9199dc

upper-constraints.txt

@@ -166,6 +166,7 @@ six===1.16.0
 SQLAlchemy===1.4.41
 stevedore===3.3.0;python_version < '3.8'
 stevedore===5.0.0;python_version >= '3.8'
+Tempita===0.5.2
 testresources===2.0.1
 testscenarios===0.5.0
 testtools===2.6.0