add netstandard support

BeckmanComms.Api.DataTransferObjects/BeckmanComms.Api.DataTransferObjects.csproj

 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net45</TargetFramework>
+    <TargetFrameworks>net45;netstandard2.0</TargetFrameworks>
     <Version>2.0.0-alpha11</Version>
     <Authors>areynold</Authors>
     <Company>Beckman Institute for Advanced Science &amp; Technology; University of Illinois at Urbana-Champaign</Company>
@@ -11,9 +11,12 @@
     <RepositoryUrl>https://gitlab.engr.illinois.edu/beckmancomms/beckmancomms-api-datatransferobjects.git</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>mvc, dto, api, beckman, uiuc, illinois</PackageTags>
-    <PackageReleaseNotes>2.0.0-alpha11:
-      * Extend PersonDto properties.
-      * Add supplemental directory DTOs (PublicationDto, PressDto, LinkDto).
+    <PackageReleaseNotes>Unreleased:
+      * Add netstandard support.
+
+2.0.0-alpha11:
+* Extend PersonDto properties.
+* Add supplemental directory DTOs (PublicationDto, PressDto, LinkDto).
       
 2.0.0-alpha10:
 * Add Status and HomeUnit properties to PersonDto.