techrep: Import cleveref last

"The cleveref package must be loaded after all other packages that do
not support it" (cleveref 0.21.4 documentation, Section 13).

The cleveref package conflicts with several other packages if loaded
before them. To allow user to use those packages, we must load it at
the very last time.

* styles/techrep.cls: Require package cleveref at \begin{document}.
4 jobs for cg/techrep in 5 minutes and 26 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Check
passed #29069
csi_reports

00:02:25

passed #29068
lrde_publis

00:01:50

 
  Publish
passed #29071
lrde.pdf

00:03:00

failed #29070
update_wiki

00:01:27

 
Name Stage Failure
failed
update_wiki Publish
    return json.loads(self._fetch_http(self._api_url, params))
File "/usr/lib/python3.5/json/__init__.py", line 319, in loads
return _default_decoder.decode(s)
File "/usr/lib/python3.5/json/decoder.py", line 339, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python3.5/json/decoder.py", line 357, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
ERROR: Job failed: exit code 1