Removed NETSTANDARD2_0 IFDefs and added Brackets (#451)

* Removed NETSTANDARD2_0 IFDefs and Fixed some brackets it wouldn't let me build if I didn't fix them

* Removed bracket changes

* Fixed Formatting hopefully

* Updated StartInfo.EnvironmentVariables from StartInfo.Environment so it is compatiable with 4.5.2

* Forgot I had changed this and didn't check git diff till now. My Bad

* Missed a spot where it was referencing Envrionment and not EnvironmentVariables

Author: KyleJFischer

src/KubernetesClient/KubernetesClientConfiguration.ConfigFile.cs

@@ -1,9 +1,7 @@
 using System;
 using System.Collections.Generic;
-#if NETSTANDARD2_0
 using Newtonsoft.Json;
 using System.Diagnostics;
-#endif
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -378,7 +376,6 @@ private void SetUserDetails(K8SConfiguration k8SConfig, Context activeContext)
                 }
             }
 
-#if NETSTANDARD2_0
             if (userDetails.UserCredentials.ExternalExecution != null)
             {
                 if (string.IsNullOrWhiteSpace(userDetails.UserCredentials.ExternalExecution.Command))
@@ -397,7 +394,6 @@ private void SetUserDetails(K8SConfiguration k8SConfig, Context activeContext)
 
                 userCredentialsFound = true;
             }
-#endif
 
             if (!userCredentialsFound)
             {
@@ -411,7 +407,6 @@ public static string RenewAzureToken(string tenantId, string clientId, string ap
             throw new KubeConfigException("Refresh not supported.");
         }
 
-#if NETSTANDARD2_0
         /// <summary>
         /// Implementation of the proposal for out-of-tree client
         /// authentication providers as described here --
@@ -432,14 +427,12 @@ public static string ExecuteExternalCommand(ExternalExecution config)
 
             var process = new Process();
 
-            process.StartInfo.Environment.Add("KUBERNETES_EXEC_INFO",
-                JsonConvert.SerializeObject(execInfo));
-
+            process.StartInfo.EnvironmentVariables.Add("KUBERNETES_EXEC_INFO", JsonConvert.SerializeObject(execInfo));
             if (config.EnvironmentVariables != null)
             {
                 foreach (var configEnvironmentVariableKey in config.EnvironmentVariables.Keys)
                 {
-                    process.StartInfo.Environment.Add(key: configEnvironmentVariableKey,
+                    process.StartInfo.EnvironmentVariables.Add(key: configEnvironmentVariableKey,
                         value: config.EnvironmentVariables[configEnvironmentVariableKey]);
                 }
             }
@@ -493,7 +486,6 @@ public static string ExecuteExternalCommand(ExternalExecution config)
                 throw new KubeConfigException($"external exec failed due to uncaught exception: {ex}");
             }
         }
-#endif
 
         /// <summary>
         ///     Loads entire Kube Config from default or explicit file path