Add pages for create/view/revoke API keys

Copying what they’ve done on GOV.UK Pay, we should let users:
- generate as many keys as they want
- only see the key at time of creation
- give keys a name
- revoke any key at any time (this should be a one way operation)

And based on discussions with @minglis and @servingUpAces, the keys should be
used in conjunction with some kind of service ID, which gets encrypted with the
key. In other words the secret itself never gets sent over the wire.

This commit adds the UI (but not the underlying API integration) for doing the
above.

app/main/forms.py

@@ -235,3 +235,7 @@ class ChangeMobileNumberForm(Form):
 
 class ConfirmMobileNumberForm(Form):
     sms_code = sms_code()
+
+
+class CreateKeyForm(Form):
+    key_name = StringField(u'Description of key')

app/main/views/api_keys.py

@@ -1,9 +1,57 @@
-from flask import render_template
+from flask import request, render_template, redirect, url_for, flash
 from flask_login import login_required
 from app.main import main
+from app.main.forms import CreateKeyForm
+
+
+@main.route("/services/<int:service_id>/documentation")
+@login_required
+def documentation(service_id):
+    return render_template('views/documentation.html', service_id=service_id)
 
 
 @main.route("/services/<int:service_id>/api-keys")
 @login_required
 def api_keys(service_id):
-    return render_template('views/api-keys.html', service_id=service_id)
+    return render_template(
+        'views/api-keys.html',
+        service_id=service_id,
+        keys=[
+            {'name': 'Test key 1', 'last_used': '12 January 2016, 10:01AM', 'id': 1},
+            {'name': 'Test key 2', 'last_used': '12 January 2016, 9:50AM', 'id': 1},
+            {'name': 'Test key 3', 'last_used': '12 January 2016, 9:49AM', 'id': 1},
+            {
+                'name': 'My first key', 'last_used': '25 December 2015, 09:49AM', 'id': 1,
+                'revoked': '4 January 2016, 6:00PM'
+            }
+        ]
+    )
+
+
+@main.route("/services/<int:service_id>/api-keys/create", methods=['GET', 'POST'])
+@login_required
+def create_api_key(service_id):
+    form = CreateKeyForm()
+    if form.validate_on_submit():
+        return redirect(url_for('.show_api_key', service_id=service_id))
+    return render_template(
+        'views/api-keys/create.html',
+        service_id=service_id,
+        key_name=form.key_name
+    )
+
+
+@main.route("/services/<int:service_id>/api-keys/show")
+@login_required
+def show_api_key(service_id):
+    return render_template('views/api-keys/show.html', service_id=service_id)
+
+
+@main.route("/services/<int:service_id>/api-keys/revoke/<int:key_id>", methods=['GET', 'POST'])
+@login_required
+def revoke_api_key(service_id, key_id):
+    if request.method == 'GET':
+        return render_template('views/api-keys/revoke.html', service_id=service_id)
+    elif request.method == 'POST':
+        flash('‘Test key 1’ was revoked')
+        return redirect(url_for('.api_keys', service_id=service_id))