replace imports of q with bluebird

update `package.json`

```
find src test -name '*.js' |
    xargs perl -i -pe 'if (/require\(.[qQ].\)/) { $_ = "import Promise from '\''bluebird'\'';\n"; }'

find src test -name '*.js' |
    xargs perl -i -pe 'if (/import [qQ] /) { $_ = "import Promise from '\''bluebird'\'';\n"; }'
```

test/app-tests/loading.js

@@ -22,7 +22,7 @@ import React from 'react';
 import ReactDOM from 'react-dom';
 import ReactTestUtils from 'react-addons-test-utils';
 import expect from 'expect';
-import q from 'q';
+import Promise from 'bluebird';
 
 import jssdk from 'matrix-js-sdk';