Fix UnicodeEncodeError for long course names

[morenopc]

I'm coming from a fresh Aspen release (OPENEDX_RELEASE=aspen.1) installation of the edX Full Stack on a single Ubuntu 12.04 64-bit at AWS E2 and after restore some courses I decided to generate some certificates. As the courses are in Portuguese most of the students and course names have non-ascii characters that should be decode using utf-8.

So I can see the decode method has been called (.decode('utf-8')) but for long course names it seems to called twice raising an UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 7: ordinal not in range(128) error.

My solution (after pull the last commits) was remove the .decode('utf-8') method ESOedX@48aa56e#diff-dca6aff9cafd628c46cf3346375d02a3R1170 (please check my commit) but I'm not sure if it's the best solution. If yes I can make a pull request.

After pull the last commits from master I got this error below which I solved removing .decode('utf-8') from COURSE_LONG=self.long_course line 1170.

/edx/app/edxapp/edx-platform$ sudo less /edx/var/log/supervisor/certstderr.log

Traceback (most recent call last):
  File "/edx/app/certs/certificates/certificate_agent.py", line 198, in <module>
    main()
  File "/edx/app/certs/certificates/certificate_agent.py", line 130, in main
    download_url) = cert.create_and_upload(name.encode('utf-8'), grade=grade, designation=designation)
  File "/edx/app/certs/certificates/gen_cert.py", line 313, in create_and_upload
    designation=designation,)
  File "/edx/app/certs/certificates/gen_cert.py", line 385, in _generate_certificate
    designation,
  File "/edx/app/certs/certificates/gen_cert.py", line 576, in _generate_v1_certificate
    self.course, self.long_course)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 7: ordinal not in range(128)