Software Público Brasileiro

- Updates rakismet version;
- Fixes akismet_data being nil;
- Creates test for rakismet gem behaviour in anti_spam plugin;
- Adds teardown to isolate tests;

Signed-off-by: Antonio Terceiro <terceiro@colivre.coop.br>
Signed-off-by: Francisco Marcelo de Araújo Lima Júnior <francisco.lima-junior@serpro.gov.br>
Signed-off-by: Marcos Ronaldo <marcos.rpj2@gmail.com>