Added Modulus deployment.

Uses the configuration options of: Token (the user's Modulus API token) and
project (the project to deploy to).

pkg/plugin/deploy/modulus.go

@@ -0,0 +1,20 @@
+package deploy
+
+import (
+	"fmt"
+	"github.com/drone/drone/pkg/build/buildfile"
+)
+
+type Modulus struct {
+	Project string `yaml:"project,omitempty"`
+	Token   string `yaml:"token,omitempty"`
+}
+
+func (m *Modulus) Write(f *buildfile.Buildfile) {
+	f.writeEnv("MODULUS_TOKEN", m.Token)
+
+	// Install the Modulus command line interface then deploy the configured
+	// project.
+	f.WriteCmdSilent("npm install -g modulus")
+	f.WriteCmd(fmt.Sprintf("modulus deploy -p '%s'", m.App))
+}