Add an example of using .basic_auth_required()

examples/basic_auth/app.py

+from flask import Flask, g, request, session, redirect, url_for
+from flask.ext.simpleldap import LDAP
+
+app = Flask(__name__)
+app.secret_key = 'dev key'
+app.debug = True
+
+app.config['LDAP_HOST'] = 'ldap.example.org'
+app.config['LDAP_BASE_DN'] = 'OU=users,dc=example,dc=org'
+app.config['LDAP_USERNAME'] = 'CN=user,OU=Users,DC=example,DC=org'
+app.config['LDAP_PASSWORD'] = 'password'
+
+ldap = LDAP(app)
+
+@app.route('/')
+@ldap.basic_auth_required
+def index():
+    return "Welcome, {0}!".format(g.ldap_username)
+
+if __name__ == '__main__':
+    app.run()