Dashboard widget for SMART PLAN

Can be merged when AlekSIS!155 (merged) is merged.

aleksis/apps/chronos/templates/chronos/partials/lessons_col.html

+{% for period, lessons in lesson_periods.items %}
+  <div class="row">
+    <div class="col s4">
+      {% include "chronos/partials/period_time.html" with period=period periods=periods %}
+    </div>
+    <div class="col s8">
+      {% include "chronos/partials/lesson.html" with lessons=lessons %}
+    </div>
+  </div>
+{% endfor %}