Add the version number of the platform to the top navbar

Currently, the version number must be updated manually in the file
`aplus/__init__.py`.

aplus/__init__.py

@@ -0,0 +1,3 @@
+__version__ = '1.11.0'
+"""The version of the A-plus platform."""
+VERSION = __version__

aplus/settings.py

@@ -217,6 +217,7 @@
                 "django.template.context_processors.media",
                 "django.template.context_processors.static",
                 "django.contrib.messages.context_processors.messages",
+                "lib.context_processors.aplus_version",
             ],
         },
     },

assets/sass/layout/_header.scss

@@ -49,6 +49,12 @@
 		}
 	}
 
+	.navbar-brand + .navbar-text {
+		float: left;
+		font-size: $font-size-small;
+		color: $gray-lighter;
+	}
+
 	.navbar-toggle .badge {
 		position: absolute;
 		right: -10px;

lib/context_processors.py

@@ -0,0 +1,9 @@
+"""Django template context processors that may be enabled in settings.py (TEMPLATES)."""
+
+from aplus import VERSION
+
+
+def aplus_version(request):
+    return {
+        'APLUS_VERSION': 'v' + VERSION,
+    }

templates/base.html

@@ -94,6 +94,7 @@
 				<div class="container-fluid">
 					<div class="navbar-header">
 						<a class="navbar-brand" href="{% url 'home' %}">{% brand_name %}</a>
+						<p class="navbar-text">{{ APLUS_VERSION }}</p>
 						<ul class="nav navbar-dropdown">
 							<li role="separator" class="divider"></li>
 							<li role="presentation" class="dropdown">