Can save and update issuers, programs
Top links go to admin instead of root.
Remove unused file.
Fix duplicate/wrong ID.
Frontend for selecting programs for badges.

Added a dropdown menu to the "new badge" & "edit badge" pages for
selecting a program. Added some text on the "show badge" page to display
which issuer and program the badge is associated with.

This commit also includes a lot of style fixes: whitespace fixes, using
`const` instead of `var` where appropriate, adding in missing
semicolons.
Upgrade nunjucks

There were some annoying bugs in the version we were using, including
broken behaviour for the `if` block in templates. Upgrading to the
latest version fixes some of those issues.
Add utility methods

* util.whitelist: create a whitelist object with an `exempt` method
* util.objWrap: higher-order function for wrapping a value in an object
* util.isEmail: test a string for email-ness.
Add template filter

Now that we have two classes of users, we can't just send everyone off
to /admin. This provides a filter so the frontend only needs to know
about the access level and the filter can determine the correct path.
Rename: routes/admin.js => routes/render.js

`admin.js` has always been a pretty poor name for this file. It's
focused entirely with rendering the frontend templates, so why not
`render.js`?
Frontend for issuing badges

This is a rather large commit containing the bare-bones necessities for
issuing badges manually. When a user signs in, we first check to see if
they are super user (as set by the environment variable). If not, we
check against each issuers' `accessList` to make a list of issuers that
a user has access to.

If a user has access to some issuers, we show the list of all the badges
related to those issuers (via their programs). The user is taken to a
screen where she can enter a list of email addresses and issue a badge
to each of them.
Remove `badges` collection from program.

While it's nice to have a two-way relationship, we are able to get by
without it and keeping it updated when a badge changes affiliation would
have been a pain.
Merge pull request #88 from mozilla/multiple-issuers-frontend

Frontend for dealing with multiple issuers
changing to res.json
merging in @brianloveswords v2.0 stuff
fixing some spacing, removing underscore map
some nits