feat: Add "coder" CLI (#221)

* feat: Add "coder" CLI

* Add CLI test for login

* Add "bin/coder" target to Makefile

* Update promptui to fix race

* Fix error scope

* Don't run CLI tests on Windows

* Fix requested changes

cli/projectplan.go

@@ -0,0 +1,16 @@
+package cli
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func projectPlan() *cobra.Command {
+	return &cobra.Command{
+		Use:   "plan <directory>",
+		Args:  cobra.MinimumNArgs(1),
+		Short: "Plan a project update from the current directory",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return nil
+		},
+	}
+}