CPU and memory usage keep increasing and can be quite high by using component.NewGraphviz()

[mengdie-song]

What steps did you take and what happened:
I am writing an octant-plugin to show graphviz.
During my test, I found that CPU and memory usage is keeping increasing and will be quite high by
using component.NewGraphviz(), even when the graph is quite simple, e.g. component.NewGraphviz("digraph {a -> b}")
I am not sure if there is any leak in this case or this is expected since the usage is increasing all the time

What did you expect to happen:
The CPU and memory will not keep increasing by using component.NewGraphviz

Environment:

• Octant version (use octant version): 0.10.2
• Kubernetes version (use kubectl version):
  Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.0", GitCommit:"70132b0f130acc0bed193d9ba59dd186f0e634cf", GitTreeState:"clean", BuildDate:"2019-12-07T21:20:10Z", GoVersion:"go1.13.4", Compiler:"gc", Platform:"linux/amd64"}
  Server Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.5", GitCommit:"e0fccafd69541e3750d460ba0f9743b90336f24f", GitTreeState:"clean",
  BuildDate:"2020-04-16T11:35:47Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
• OS (macOS 10.15, Windows 10, Ubuntu 19.10 etc):
  Ubuntu 18.04.3 LTS