upgraded to Akka.NET v1.5.0-beta3 (#183)

Author: Aaronontheweb

src/Akka.Persistence.PostgreSql.sln

@@ -9,7 +9,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Akka.Persistence.PostgreSql
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{118AFA68-6532-498C-8037-A6151FD7A655}"
 	ProjectSection(SolutionItems) = preProject
-		common.props = common.props
 		..\README.md = ..\README.md
 	EndProjectSection
 EndProject

src/Directory.Build.props

@@ -14,7 +14,7 @@
   <PropertyGroup>
     <XunitVersion>2.4.2</XunitVersion>
     <XunitRunnerVersion>2.4.5</XunitRunnerVersion>
-    <AkkaVersion>1.4.49</AkkaVersion>
+    <AkkaVersion>1.5.0-beta3</AkkaVersion>
     <PostgresLowVersion>5.0.11</PostgresLowVersion>
     <PostgresHighVersion>6.0.7</PostgresHighVersion>
     <PostgresVersion>[$(PostgresLowVersion), $(PostgresHighVersion)]</PostgresVersion>