Added mime type for MS Outlook application

Added content type ‘application/vnd.ms-outlook’ for the application MS
Outlook with the file extension ‘.msg’. This is not registered in IANA
but found the content type at
http://www.digitalpreservation.gov/formats/fdd/fdd000379.shtml.

Made changes to avoid failure on travis

Reverted back the changes
Merge branch 'MS_Outlook' of github.com:keerthisiv/mime-types into keerthisiv-MS_Outlook

* 'MS_Outlook' of github.com:keerthisiv/mime-types:
  Added mime type for MS Outlook application
Merge branch 'keerthisiv-MS_Outlook' into 2.4-experiments

* keerthisiv-MS_Outlook:
  Added mime type for MS Outlook application