Add provider versions (#74)

README.md

@@ -249,9 +249,9 @@ The following resources _CAN_ be created:
 
 | Name | Version |
 |------|---------|
-| <a name="provider_aws"></a> [aws](#provider\_aws) | n/a |
-| <a name="provider_null"></a> [null](#provider\_null) | n/a |
-| <a name="provider_random"></a> [random](#provider\_random) | n/a |
+| <a name="provider_aws"></a> [aws](#provider\_aws) | ~> 4.0 |
+| <a name="provider_null"></a> [null](#provider\_null) | ~> 3.0 |
+| <a name="provider_random"></a> [random](#provider\_random) | ~> 3.0 |
 
 <!-- TFDOCS_PROVIDER_END -->
 
@@ -260,7 +260,10 @@ The following resources _CAN_ be created:
 
 | Name | Version |
 |------|---------|
-| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.0.0 |
+| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.0 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | ~> 4.0 |
+| <a name="requirement_null"></a> [null](#requirement\_null) | ~> 3.0 |
+| <a name="requirement_random"></a> [random](#requirement\_random) | ~> 3.0 |
 
 <!-- TFDOCS_REQUIREMENTS_END -->
 

versions.tf

@@ -1,4 +1,17 @@
-
 terraform {
-  required_version = ">= 1.0.0"
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 4.0"
+    }
+    null = {
+      source  = "hashicorp/null"
+      version = "~> 3.0"
+    }
+    random = {
+      source  = "hashicorp/random"
+      version = "~> 3.0"
+    }
+  }
+  required_version = ">= 1.0"
 }