Automated SDK update

This updates the SDK from internal repo commit segmentio/public-api@b48cd468.

Author: APIs and Common Services team

Segment.PublicApi.sln

@@ -2,18 +2,18 @@
 # Visual Studio 2012
 VisualStudioVersion = 12.0.0.0
 MinimumVisualStudioVersion = 10.0.0.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Segment.PublicApi", "src\Segment.PublicApi\Segment.PublicApi.csproj", "{251A2A8E-ED10-482D-A1D4-5B324FD1F293}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Segment.PublicApi", "src\Segment.PublicApi\Segment.PublicApi.csproj", "{DB75F858-0FD5-4620-B09B-458DC0053E9F}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{251A2A8E-ED10-482D-A1D4-5B324FD1F293}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{251A2A8E-ED10-482D-A1D4-5B324FD1F293}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{251A2A8E-ED10-482D-A1D4-5B324FD1F293}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{251A2A8E-ED10-482D-A1D4-5B324FD1F293}.Release|Any CPU.Build.0 = Release|Any CPU
+		{DB75F858-0FD5-4620-B09B-458DC0053E9F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{DB75F858-0FD5-4620-B09B-458DC0053E9F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{DB75F858-0FD5-4620-B09B-458DC0053E9F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{DB75F858-0FD5-4620-B09B-458DC0053E9F}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/Segment.PublicApi/Model/AudienceOptions.cs

@@ -36,7 +36,7 @@ public partial class AudienceOptions : IEquatable<AudienceOptions>, IValidatable
         /// Initializes a new instance of the <see cref="AudienceOptions" /> class.
         /// </summary>
         /// <param name="includeHistoricalData">Determines whether data prior to the audience being created is included when determining audience membership. Note that including historical data may be needed in order to properly handle the definition specified. In these cases, Segment will automatically handle including historical data and the response will return the includeHistoricalData parameter as true..</param>
-        /// <param name="filterByExternalIds">The set of profile external identifiers being used to determine audience membership. Profiles will only be considered for audience membership if the profile has at least one external id whose key matches a value in this set..</param>
+        /// <param name="filterByExternalIds">The set of profile external identifiers being used to determine audience membership. Profiles will only be considered for audience membership if the profile has at least one external id whose key matches a value in this set. If unspecified, a default set of external identifiers will be used: [&#39;user_id&#39;, &#39;email&#39;, &#39;android.idfa&#39;, &#39;ios.idfa&#39;]..</param>
         /// <param name="backfillEventDataDays">If specified, the value of this field indicates the number of days, specified from the date the audience was created, that event data will be included from when determining audience membership. If unspecified, defer to the value of &#x60;includeHistoricalData&#x60; to determine whether historical data is either entirely included or entirely excluded when determining audience membership..</param>
         public AudienceOptions(bool includeHistoricalData = default(bool), List<string> filterByExternalIds = default(List<string>), decimal backfillEventDataDays = default(decimal))
         {
@@ -53,9 +53,9 @@ public partial class AudienceOptions : IEquatable<AudienceOptions>, IValidatable
         public bool IncludeHistoricalData { get; set; }
 
         /// <summary>
-        /// The set of profile external identifiers being used to determine audience membership. Profiles will only be considered for audience membership if the profile has at least one external id whose key matches a value in this set.
+        /// The set of profile external identifiers being used to determine audience membership. Profiles will only be considered for audience membership if the profile has at least one external id whose key matches a value in this set. If unspecified, a default set of external identifiers will be used: [&#39;user_id&#39;, &#39;email&#39;, &#39;android.idfa&#39;, &#39;ios.idfa&#39;].
         /// </summary>
-        /// <value>The set of profile external identifiers being used to determine audience membership. Profiles will only be considered for audience membership if the profile has at least one external id whose key matches a value in this set.</value>
+        /// <value>The set of profile external identifiers being used to determine audience membership. Profiles will only be considered for audience membership if the profile has at least one external id whose key matches a value in this set. If unspecified, a default set of external identifiers will be used: [&#39;user_id&#39;, &#39;email&#39;, &#39;android.idfa&#39;, &#39;ios.idfa&#39;].</value>
         [DataMember(Name = "filterByExternalIds", EmitDefaultValue = false)]
         public List<string> FilterByExternalIds { get; set; }