Updated del to version 1.1.0
Returned gulp streams as this makes them asynchronous from gulps perspective
Fixed version checking
Fixed behaviour of exports global
Bumped version number
Merge branch 'release/1.1.0'
Merge tag '1.1.0' into develop

New version includes the following:
  - a bugfix for the behaviour of the global 'exports'
  - bumped the version of del to 1.1.0
  - updated some of the tests to return streams
Reverted travis badge