feat: implement ping command (#31)

* build: use deepmap/oapi-codegen to generate an HTTP client
* feat: add global CLI options
* feat: load local config to find host and token
* feat: implement ping command
* test: add unit tests for ping command

internal/cli.go

@@ -0,0 +1,15 @@
+package internal
+
+import (
+	"io"
+
+	"github.com/influxdata/influx-cli/v2/internal/api"
+)
+
+type CLI struct {
+	Stdin  io.Reader
+	Stdout io.Writer
+	Stderr io.Writer
+
+	TraceId *api.TraceSpan
+}