Build and install welab-rn-front-end into iOS simulator

       Precondition:

        1.  install yarn at mac  

            brew install yarn

       2. install xcode and Xcode Command Line Tools from mac app store, confirm that the version of MacOS, xcode, xcode command line tools are consistent with each other.

         for example:

           MacOS: 12.0.1

           XCODE: 13.1

           XCODE command-line tool: 13.1

        3. install cocoapods

            MacOS version    > 11.3  

             sudo gem install -n /usr/local/bin cocoapods -v 1.11.2

Mac安装CocoaPods详解 - 简书

     if use welab-rn-front-end project

• clone welab main app project: welab-rn-front-end, and go to branch feature/wealth/develop.
• pull the latest code
• find package.json, and update "@welab/wealth-sdk" to the latest version.( you can also ignore this step, and you will need to select a version in final build step).
• execute the command: yarn.   If there is error that fail to download dependency from third-party, like github, google, then connect to EPAM VPN and execute "yarn" again. If there is error that fail to download dependency from gitlab(welab repository), then disconnect EPAM VPN and execute "yarn" again. especially for "react-native-cert-pinner": "Yarn for mac 安装教程 - 掘金GitHub - approov/react-native-cert-pinner: Strengthens TLS in React Native through Certificate Pinning" on package.json, need to remove the other dependecies to execute "yarn" command, and add them back after this pinner is downloaded.
• execute the command: yarn preios. Also need to connect/disconnect to download dependencies. if  such error occurs, 
• execute the command: yarn start. and need to keep this terminal alive.
• execute the command: yarn ios:sim

     if use wealthsdk project

• clone https://gitlab.prod-ss.welabts.net/vb/wealth/wealthsdk.git and use branch develop
• execute command: yarn
• go to ios folder and execute command: pod install
• back to wealthsdk path and execute command: yarn start, and need to keep this terminal alive.
• edit username/password on {wealthsdk}/src/config/config.sit.ts
• still in wealthsdk path and execute command: yarn run ios [--simulator='simulator name'].