Add basic ci

[boundless-forest]

Add basic ci

Now, we just retain some basic check scripts, list as following:

• fmt
• security audit
• clippy
• release

Temporarily ignore security audit. I came cross a error because of memoffset's bug.

ID:	 RUSTSEC-2019-0011
Crate:	 memoffset
Version: 0.2.1
Date:	 2019-07-16
URL:	 https://github.com/Gilnaa/memoffset/issues/9#issuecomment-505461490
Title:	 Flaw in offset_of and span_of causes SIGILL, drops uninitialized memory of arbitrary type on panic in client code
Solution: upgrade to: >= 0.5.0

Fix steps:

1. update cita_logger's dependence of cross-beam
2. update all crate relevant with crossbeam in cita-common, include pubsub*, engine, tokio-core
3. update cita using new cita-common

Reference

Memoffset bug Info
Cross-beam issue
Tokio issue