Add blog post about workshop at UFRGS

@acviana Could you take a look on this?
The `ã` at this line is the reason that `make site` fail:

~~~
$ make site
make SITE=/home/raniere/documents/software_carpentry/site/_site OUT=/home/raniere/documents/software_carpentry/site/_site build
make[1]: Entering directory '/home/raniere/documents/software_carpentry/site'
python ./bin/preprocess.py -c ./config -o /home/raniere/documents/software_carpentry/site/_site -s /home/raniere/documents/software_carpentry/site/_site
jekyll build -d /home/raniere/documents/software_carpentry/site/_site
Configuration file: /home/raniere/documents/software_carpentry/site/_config.yml
            Source: /home/raniere/documents/software_carpentry/site
       Destination: /home/raniere/documents/software_carpentry/site/_site
      Generating... 
                    done.
python ./bin/make_calendar.py -o /home/raniere/documents/software_carpentry/site/_site -s /home/raniere/documents/software_carpentry/site/_site
python ./bin/make_rss_feed.py -o /home/raniere/documents/software_carpentry/site/_site -s /home/raniere/documents/software_carpentry/site/_site
Traceback (most recent call last):
  File "./bin/make_rss_feed.py", line 149, in <module>
    main()
  File "./bin/make_rss_feed.py", line 25, in main
    selection)
  File "./bin/make_rss_feed.py", line 72, in build_blog_rss
    rss.write_xml(writer)
  File "/home/raniere/documents/software_carpentry/site/bin/PyRSS2Gen.py", line 73, in write_xml
    self.publish(handler)
  File "/home/raniere/documents/software_carpentry/site/bin/PyRSS2Gen.py", line 419, in publish
    item.publish(handler)
  File "/home/raniere/documents/software_carpentry/site/bin/PyRSS2Gen.py", line 468, in publish
    self.publish_extensions(handler)
  File "./bin/make_rss_feed.py", line 144, in publish_extensions
    { 'e':'content:encoded', 'c':unicode(self.content)})
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 1905: ordinal not in range(128)
Makefile:190: recipe for target '/home/raniere/documents/software_carpentry/site/_site/feed.xml' failed
make[1]: *** [/home/raniere/documents/software_carpentry/site/_site/feed.xml] Error 1
make[1]: Leaving directory '/home/raniere/documents/software_carpentry/site'
Makefile:136: recipe for target 'site' failed
make: *** [site] Error 2
~~~

@gvwilson do you know how to solve this problem or should I use a workaround (e.g. replace "University of São Paulo" by "USP")?