Update issue templates

---

name: ":bug: Bug report"

about: Create a bug report to help us improve Milvus

title: "[BUG]"

labels: ''

assignees: ''

---

**Describe the bug**

A clear and concise description of what the bug is.

**Steps/Code to reproduce behavior**

Follow this [guide](http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports) to craft a minimal bug report. This helps us reproduce the issue you're having and resolve the issue more quickly.

**Expected behavior**

A clear and concise description of what you expected to happen.

**Environment details**

- Hardware/Softward conditions (OS, CPU, GPU, Memory)

- Method of installation (Docker, or from source)

- Milvus version (v0.3.1, or v0.4.0)

- Milvus configuration (Settings you made in `server_config.yaml`)

**Screenshots**

If applicable, add screenshots to help explain your problem.

**Additional context**

Add any other context about the problem here.