Update issue templates

Former-commit-id: f2a6152a0a589dadc7ea94569ea312f1e5aac41a

.github/ISSUE_TEMPLATE/-bug--bug-report.md

+---
+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.