add Dockerfiles for tfenv, tfswitch
diff --git a/scripts/development/Dockerfile.tfenv b/scripts/development/Dockerfile.tfenv
new file mode 100644
index 0000000..16a5ee6
--- /dev/null
+++ b/scripts/development/Dockerfile.tfenv
@@ -0,0 +1,21 @@
+FROM golang:1.15-alpine
+
+RUN apk update && apk add bash git unzip curl
+
+# install tfenv
+RUN git clone https://github.com/tfutils/tfenv.git ~/.tfenv && \
+    ln -s ~/.tfenv/bin/* /usr/local/bin
+
+# initialise go program
+RUN mkdir ~/example
+COPY main.go ~/example/
+WORKDIR ~/example
+RUN go mod init github.com/kmoe/example
+
+# run test program without any terraform version installed
+RUN go run main.go
+
+# install 0.13.4 via tfenv
+RUN tfenv install 0.13.4 && tfenv use 0.13.4
+
+RUN go run main.go
\ No newline at end of file
diff --git a/scripts/development/Dockerfile.tfswitch b/scripts/development/Dockerfile.tfswitch
new file mode 100644
index 0000000..ddd7c71
--- /dev/null
+++ b/scripts/development/Dockerfile.tfswitch
@@ -0,0 +1,20 @@
+FROM golang:1.15-alpine
+
+RUN apk update && apk add bash git unzip curl
+
+# install tfswitch
+RUN go get github.com/warrensbox/terraform-switcher
+
+# initialise go program
+RUN mkdir ~/example
+COPY main.go ~/example/
+WORKDIR ~/example
+RUN go mod init github.com/kmoe/example
+
+# run test program without any terraform version installed
+RUN go run main.go
+
+# install 0.13.4 via tfswitch
+RUN terraform-switcher 0.13.4
+
+RUN go run main.go
\ No newline at end of file
diff --git a/scripts/development/main.go b/scripts/development/main.go
new file mode 100644
index 0000000..82a75e6
--- /dev/null
+++ b/scripts/development/main.go
@@ -0,0 +1,35 @@
+// an example application using tfexec
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/terraform-exec/tfexec"
+	"github.com/hashicorp/terraform-exec/tfinstall"
+)
+
+func main() {
+	execPath, err := tfinstall.Find(context.Background(), tfinstall.LookPath(), tfinstall.ExactVersion("0.13.3", "/tmp"))
+	if err != nil {
+		panic(err)
+	}
+
+	workingDir := "/tmp"
+	tf, err := tfexec.NewTerraform(workingDir, execPath)
+	if err != nil {
+		panic(err)
+	}
+
+	err = tf.Init(context.Background())
+	if err != nil {
+		panic(err)
+	}
+
+	tfVersion, _, err := tf.Version(context.Background(), true)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("successfully initialised Terraform version %s", tfVersion)
+}