If options.styles is not an array make it an array
If options.styles is not an array make it an array

nikhilmodak/gulp-ngdocs,manuelro/gulp-ngdocs,hans-helms/gulp-ngdocs,Thellior/gulp-ngdocs,michaelbazos/gulp-ngdocs,cpaof/gulp-ngdocs,heran/gulp-fakedocs,paul-barry-kenzan/gulp-ngdocs,alizarion/gulp-ngdocs,whitneyit/gulp-ngdocs-manuelro