Output Terraform lib version in version string (camptocamp#75)

* Add compatibility matrix to README

* Output Terraform compatibility in logs and version string

Author: raphink

README.md

@@ -171,6 +171,16 @@ sign out of the proxy.
 $ go get github.com/camptocamp/terraboard
 ```
 
+## Compatibility Matrix
+
+|Terraboard|Max Terraform version|
+|----------|---------------------|
+| 0.15.0   |  0.12.7             |
+| 0.16.0   |  0.12.7             |
+| 0.17.0   |  0.12.18            |
+| 0.18.0   |  0.12.18            |
+
+
 ## Development
 
 ### Architecture

config/config.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 
+	tfversion "github.com/hashicorp/terraform/version"
 	"github.com/jessevdk/go-flags"
 	log "github.com/sirupsen/logrus"
 	"gopkg.in/yaml.v2"
@@ -107,7 +108,7 @@ func LoadConfig(version string) *Config {
 	}
 
 	if c.Version {
-		fmt.Printf("Terraboard v%v\n", version)
+		fmt.Printf("Terraboard v%v (built for Terraform v%v)\n", version, tfversion.Version)
 		os.Exit(0)
 	}
 

main.go

@@ -14,6 +14,7 @@ import (
 	"github.com/camptocamp/terraboard/db"
 	"github.com/camptocamp/terraboard/state"
 	"github.com/camptocamp/terraboard/util"
+	tfversion "github.com/hashicorp/terraform/version"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -139,7 +140,7 @@ func main() {
 
 	util.SetBasePath(c.Web.BaseURL)
 
-	log.Infof("Terraboard v%s is starting...", version)
+	log.Infof("Terraboard v%s (built for Terraform v%s) is starting...", version, tfversion.Version)
 
 	err := c.SetupLogging()
 	if err != nil {