(chocolateyGH-689) Report install work w/non-POSH pkgs

If a package is a dependency or has no PowerShell, it should still
clean up env vars between the two packages.

src/chocolatey/infrastructure.app/builders/ConfigurationBuilder.cs

@@ -437,10 +437,15 @@ private static void set_environment_options(ChocolateyConfiguration config)
             config.Information.IsProcessElevated = ProcessInformation.process_is_elevated();
         }
 
-        public static void set_environment_variables(ChocolateyConfiguration config)
+        public static void reset_environment_variables(ChocolateyConfiguration config)
         {
             Environment.SetEnvironmentVariable("ChocolateyPackageInstallLocation", null);
             Environment.SetEnvironmentVariable("ChocolateyInstallerType", null);
+        }
+
+        public static void set_environment_variables(ChocolateyConfiguration config)
+        {
+            reset_environment_variables(config);
 
             Environment.SetEnvironmentVariable(ApplicationParameters.ChocolateyInstallEnvironmentVariableName, ApplicationParameters.InstallLocation);
             Environment.SetEnvironmentVariable("CHOCOLATEY_VERSION", config.Information.ChocolateyVersion);

src/chocolatey/infrastructure.app/services/ChocolateyPackageService.cs

@@ -20,6 +20,7 @@ namespace chocolatey.infrastructure.app.services
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
+    using builders;
     using commandline;
     using configuration;
     using domain;
@@ -271,6 +272,7 @@ public void randomly_notify_about_pro_business(ChocolateyConfiguration config, s
 
         public void handle_package_result(PackageResult packageResult, ChocolateyConfiguration config, CommandNameType commandName)
         {
+            ConfigurationBuilder.reset_environment_variables(config);
             set_pending(packageResult, config);
             var pkgInfo = _packageInfoService.get_package_information(packageResult.Package);
             if (config.AllowMultipleVersions)