Use the bundled NETStandard.Library package in netstandard targeting libraries

build/dependencies.props

@@ -4,6 +4,7 @@
     <CoreFxVersion>4.3.0</CoreFxVersion>
     <InternalAspNetCoreSdkVersion>2.0.0-*</InternalAspNetCoreSdkVersion>
     <MoqVersion>4.7.1</MoqVersion>
+    <NETStandardImplicitPackageVersion>$(BundledNETStandardPackageVersion)</NETStandardImplicitPackageVersion>
     <RedisVersion>1.1.605</RedisVersion>
     <TestSdkVersion>15.0.0</TestSdkVersion>
     <XunitVersion>2.2.0</XunitVersion>