File Upload allowed_types issue

I am trying to upload a .jpeg file using the CI uploader. Doing a migration from C1 2.x to CI 3.0

Code:

$config['upload_path'] =  $this->imgUploadFolder;
$config['allowed_types'] = 'gif|jpg|png|JPG|GIF|PNG|jpeg|JPEG';
$config['max_size'] = '1000';
$config['file_name'] = $name;

//Load the upload library
$this->load->library('upload', $config);
//attempt upload
$this->upload->do_upload()) <-- is returing false due to invalid file type

To debug, I dumped the data coming to the upload library 
The file type is recognized as image/jpeg
File name is correctly displayed - jamesgregory.jpeg
File extension is correctly displayed as .jpeg
The is_allowed_filetype function in Upload.php returns FALSE.

PHP Code:

public function is_allowed_filetype($ignore_mime = FALSE)
    {
        if ($this->allowed_types === '*')
        {
            return TRUE;
        }

        if (empty($this->allowed_types) OR ! is_array($this->allowed_types))
        {
            $this->set_error('upload_no_file_types');
            return FALSE;
        }

        $ext = strtolower(ltrim($this->file_ext, '.'));

        if ( ! in_array($ext, $this->allowed_types, TRUE))
        {
            return FALSE;
        }

        // Images get some additional checks
        if (in_array($ext, array('gif', 'jpg', 'jpeg', 'jpe', 'png'), TRUE) && @getimagesize($this->file_temp) === FALSE)
        {
            return FALSE;
        }

        if ($ignore_mime === TRUE)
        {
            return TRUE;
        }

        if (isset($this->_mimes[$ext]))
        {
            return is_array($this->_mimes[$ext])
                ? in_array($this->file_type, $this->_mimes[$ext], TRUE)
                : ($this->_mimes[$ext] === $this->file_type);
        }

        return FALSE;
    } 


It seems to pass every check and end up at the final return FALSE. 
Stumped!

This was a config issue. I had overlooked to copy mimes.php from the 3.1.