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/test-utils.js

@@ -1,7 +1,7 @@
 "use strict";
 
 import sinon from 'sinon';
-import q from 'q';
+import Promise from 'bluebird';
 
 import peg from '../src/MatrixClientPeg';
 import dis from '../src/dispatcher';