Replace Travis with GitHub actions and fix many typos (#1657)

* Create django.yml

* Fix working directory

* ..

* .

* ..

* a.

* ..

* .

* Fix typo

* Install hunspell

* maxfail

* Fix install

* .

* Reduce number of typos

* Even less typos

* Postgres debug

* Spelling fixes, yet again

* Postgres with PW

* Fix failing test

* New workflows

* Fix syntax error

* Install gettext

* Test aginst python 3.6 as well

* Clean up strategies

* Add badge, do not ignore migrations

* Use pip cache

src/pretix/control/forms/subevents.py

@@ -254,7 +254,7 @@ class RRuleForm(forms.Form):
         widget=forms.RadioSelect
     )
     count = forms.IntegerField(
-        label=_('Number of repititions'),
+        label=_('Number of repetitions'),
         initial=10
     )
     until = forms.DateField(