build/Dependencies.props: Downgraded Microsoft.Extensions.Configuration to 2.0.0 to allow applications using older versions to avoid conflicts (#388)

diff --git a/build/Dependencies.props b/build/Dependencies.props
index 522ba2a..623c5fe 100644
--- a/build/Dependencies.props
+++ b/build/Dependencies.props
@@ -50,7 +50,7 @@
     <MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion_NET4_5_1>$(MicrosoftExtensionsConfigurationPackageVersion_NET4_5_1)</MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion_NET4_5_1>
     <MicrosoftExtensionsConfigurationJsonPackageVersion_NET4_5_1>$(MicrosoftExtensionsConfigurationPackageVersion_NET4_5_1)</MicrosoftExtensionsConfigurationJsonPackageVersion_NET4_5_1>
     <MicrosoftExtensionsConfigurationXmlPackageVersion_NET4_5_1>$(MicrosoftExtensionsConfigurationPackageVersion_NET4_5_1)</MicrosoftExtensionsConfigurationXmlPackageVersion_NET4_5_1>
-    <MicrosoftExtensionsConfigurationPackageVersion>3.1.3</MicrosoftExtensionsConfigurationPackageVersion>
+    <MicrosoftExtensionsConfigurationPackageVersion>2.0.0</MicrosoftExtensionsConfigurationPackageVersion>
     <MicrosoftExtensionsConfigurationAbstractionsPackageVersion>$(MicrosoftExtensionsConfigurationPackageVersion)</MicrosoftExtensionsConfigurationAbstractionsPackageVersion>
     <MicrosoftExtensionsConfigurationCommandLinePackageVersion>$(MicrosoftExtensionsConfigurationPackageVersion)</MicrosoftExtensionsConfigurationCommandLinePackageVersion>
     <MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion>$(MicrosoftExtensionsConfigurationPackageVersion)</MicrosoftExtensionsConfigurationEnvironmentVariablesPackageVersion>