Merge tag 'v1.7.0' into develop

v1.7.0
Merge branch 'hotfix/fonts-with-https' into develop
make active in admin
add an error message on duplicate email in subscribe form
Revert "Revert "Prevent creation of relationship with same entity as existing relationship #521""

This reverts commit 506fa015e96011124aacc58e9ede3c4ced2af116.
orphans
Merge tag 'login-fix' into develop

Hotfix signup unvalid username
Merge branch 'master' into develop
Added link to investigation in form footer #498 + added fa-check #503
ContributeCtrl: never update in the same time data
add login link to duplicate mail error message on subscribe form
email warning message
Added condition to should_have_credits inner method (TopicResource.hydrate_about) #542
Added test for #542 bug
Integer entries in composite relationship fields do not show in popover #455
Updated app.urls to handle new username format (with special chars)
Removed @ from app.url user urls patterns
Updated username validation patterns -> removed @ and + from accepted chars
Bump to v1.7.3
[existing relationship behaviour] message updated #532