How to Release Podspec

Update all the files needed

Bump the pod version in the VinliNet.podspec:

s.version
```
s.version      = "1.4.0"
```

s.source

s.source       = { :git => "https://github.com/vinli/ios-net.git", :tag => "1.4.0" }

Test to make sure there will be no errors:
```
pod lib lint
```
Push the podspec to the Cocoapod trunk. If there are warnings, it should be safe to disable them:
```
pod trunk push VinliNet.podspec --allow-warnings
```