Add different solutions to AWS exercises

Not only console solutions, but also Terraform and Pulumi.

In addition, this change fixes issues #279 and #280

topics/aws/exercises/subnets/pulumi/__main__.py

@@ -0,0 +1,27 @@
+import pulumi
+import pulumi_aws as aws
+
+availableZones = pulumi_aws.get_availability_zones(state="available")
+
+aws.ec2.Subnet("NewSubnet1",
+    vpc_id=aws_vpc["main"]["id"],
+    cidr_block="10.0.0.0/24",
+    availability_zone=availableZones.names[0],
+    tags={"Name": "NewSubnet1"}
+    )
+
+aws.ec2.Subnet("NewSubnet2",
+    vpc_id=aws_vpc["main"]["id"],
+    cidr_block="10.0.1.0/24",
+    availability_zone=availableZones.names[1]
+    tags={"Name": "NewSubnet2"}
+    )
+
+aws.ec2.Subnet("NewSubnet3",
+    vpc_id=aws_vpc["main"]["id"],
+    cidr_block="10.0.2.0/24",
+    availability_zone=availableZones.names[2]
+    tags={"Name": "NewSubnet3"}
+    )
+
+# Run "pulumi up"