Bump AkkaVersion from 1.4.16 to 1.4.19 (#96)

Bumps `AkkaVersion` from 1.4.16 to 1.4.19.

Updates `Akka.Persistence.Sql.Common` from 1.4.16 to 1.4.19
- [Release notes](https://github.com/akkadotnet/akka.net/releases)
- [Changelog](https://github.com/akkadotnet/akka.net/blob/dev/RELEASE_NOTES.md)
- [Commits](akkadotnet/akka.net@1.4.16...1.4.19)

Updates `Akka.Persistence.Sql.TestKit` from 1.4.16 to 1.4.19
- [Release notes](https://github.com/akkadotnet/akka.net/releases)
- [Changelog](https://github.com/akkadotnet/akka.net/blob/dev/RELEASE_NOTES.md)
- [Commits](akkadotnet/akka.net@1.4.16...1.4.19)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Aaron Stannard <aaron@petabridge.com>

src/common.props

@@ -14,7 +14,7 @@
   <PropertyGroup>
     <XunitVersion>2.4.1</XunitVersion>
     <XunitRunnerVersion>2.4.3</XunitRunnerVersion>
-    <AkkaVersion>1.4.16</AkkaVersion>
+    <AkkaVersion>1.4.19</AkkaVersion>
     <PostgresVersion>5.0.3</PostgresVersion>
     <NetStandardLibVersion>netstandard2.0</NetStandardLibVersion>
     <NetFrameworkVersion>net45</NetFrameworkVersion>