Check mail d'invitation ok

[jblagadec]

Preview accessible ici : http://localhost:8071/debug/mail/invitation_html

[mjeammet]

@sdemagny @jblagadec can we close this issue ?

[jblagadec]

@sdemagny @jblagadec can we close this issue ?

As for me, yes ; I'll let @sdemagny comment too