removed newsletter function
fixed error
readied migrations for creatingTables and added new migrations for drop_table
Merge pull request #458 from hpi-swt2/feature/remove-newsletters

removed newsletter function
Merge branch 'develop'
removed newsletter associations
solved #432
basic import for new alumni approach
a little bit of cleanup
removed unnecessary space
email and first link logic
Merge pull request #465 from hpi-swt2/feature/432_student_index

Feature/432 student index
working alumni import flow
registration of alumni addresses available to everyone
Merge branch 'develop' into feature/alumni-import
new email address
Merge branch 'feature/alumni-import' into feature/hpi-email
new email for alumni mailer
sendmail config
hpi email in tests