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"; }'
```

src/components/views/settings/Notifications.js

@@ -17,7 +17,7 @@ limitations under the License.
 'use strict';
 var React = require('react');
 import { _t, _tJsx } from 'matrix-react-sdk/lib/languageHandler';
-var q = require("q");
+import Promise from 'bluebird';
 var sdk = require('matrix-react-sdk');
 var MatrixClientPeg = require('matrix-react-sdk/lib/MatrixClientPeg');
 var UserSettingsStore = require('matrix-react-sdk/lib/UserSettingsStore');