Add event checkin functionality, seperate power tests into a different form (#536)

* Split power related parts of event checklist into a seperate form

* Revamp H&S overview, remove individual lists.

They were not a good thing.

* Remove old 'vehicle/crew' stuff

* Very initial version of checkin form

* Further work on checkin, add role field etc

* Fix tests after form split

* Add ability to edit checkins, more validation

* Basic checkin/out logic complete

* Add homepage checkin for events happening now

* Minor improvement to homepage UI

* Checkin button turns into checkout button where applicable

* UI work

* Clicking check out does not redirect the user

* Register check in model with the admin site

* Add power record status chip, checklist status chip displays number of checklists

* Minor fixes

* Implement codedoctor suggestions

* pep8

* Add data migration for crew/vehicles

* Checkin only requires login (no perms) and block users from editing other checkins at Django level

templates/index.html

@@ -8,6 +8,13 @@
 <div class="row">
     <h1 class="col-sm-12 pb-3">R<small class="text-muted">ig</small> I<small class="text-muted">nformation</small> G<small class="text-muted">athering</small> S<small class="text-muted">ystem</small></h1>
     <h2 class="col-sm-12 pb-3">Welcome back {{ user.get_full_name }}, there {%if rig_count == 1 %}is one rig coming up{%else%}are {{ rig_count|apnumber }} rigs coming up.{%endif%}</h2>
+    {% if now %}
+    <div class="col-sm-12 alert alert-primary rounded-0 mx-auto">
+    {% for event in now %}
+    Event {{ event }} is happening now! <a href="{% url 'event_checkin' event.pk %}" class="btn btn-success btn-sm modal-href align-baseline {% if request.user.current_event %}disabled{%endif%}"><span class="fas fa-user-clock"></span> <span class="d-none d-sm-inline">Check In</span></a><br/>
+    {% endfor %}
+    </div>
+    {% endif %}
     <div class="col-sm-4 mb-3">
         <div class="card">
             <img class="card-img-top d-none d-sm-block" src="{% static 'imgs/rigs.jpg' %}" alt="Some lights and haze, very purple" style="height: 150px; object-fit: cover;">
@@ -24,7 +31,6 @@
     </div>
     <div class="col-sm-4 mb-3">
         <div class="card">
-            {% now "m-d" as todays_date %}
             <img class="card-img-top d-none d-sm-block" src="{% if todays_date == '04-01' %}{% static 'imgs/tappytaptap.gif' %}{%else%}{% static 'imgs/assets.jpg' %}{%endif%}" alt="M32 sound desk close up of the faders" style="height: 150px; object-fit: cover;">
             <h4 class="card-header">Asset Database</h4>
             <div class="list-group list-group-flush">