Always copy embedded.mobileprovision

The `embedded.mobileprovision` should always be copied over in the codesign step. Otherwise subsequent builds with a different provisioning profile will build an incorrect app bundle.
Example use case:
```
rake enterprise # Build an adhoc distribution
rake appstore # Build an appstore release
```
Merge pull request #121 from bracki/patch-1

Always copy over embedded.mobileprovision