Add test for `GitHub::search_code`.
Add test for `GitHub::search_code`.

EricFromCanada/brew,muellermartin/dist,palxex/brew,rwhogg/brew,mgrimes/brew,jmsundar/brew,palxex/brew,mgrimes/brew,tonyg/homebrew,sjackman/homebrew,vitorgalvao/brew,bfontaine/brew,hanxue/linuxbrew,konqui/brew,nandub/brew,hanxue/linuxbrew,mahori/brew,MikeMcQuaid/brew,claui/brew,Homebrew/brew,maxim-belkin/brew,bfontaine/brew,sjackman/homebrew,pseudocody/brew,sjackman/homebrew,ilovezfs/brew,konqui/brew,konqui/brew,jmsundar/brew,amar-laksh/brew_sudo,rwhogg/brew,reitermarkus/brew,MikeMcQuaid/brew,aw1621107/brew,amar-laksh/brew_sudo,ilovezfs/brew,EricFromCanada/brew,zmwangx/brew,nandub/brew,bfontaine/brew,gregory-nisbet/brew,EricFromCanada/brew,reitermarkus/brew,aw1621107/brew,Linuxbrew/brew,mahori/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,JCount/brew,nandub/brew,amar-laksh/brew_sudo,reelsense/brew,mahori/brew,zmwangx/brew,mahori/brew,Linuxbrew/brew,nandub/brew,Homebrew/brew,maxim-belkin/brew,mgrimes/brew,EricFromCanada/brew,DomT4/brew,DomT4/brew,konqui/brew,alyssais/brew,JCount/brew,tonyg/homebrew,Homebrew/brew,claui/brew,vitorgalvao/brew,DomT4/brew,muellermartin/dist,reitermarkus/brew,alyssais/brew,gregory-nisbet/brew,alyssais/brew,Linuxbrew/brew,palxex/brew,tonyg/homebrew,JCount/brew,Homebrew/brew,reitermarkus/brew,claui/brew,Linuxbrew/brew,jmsundar/brew,hanxue/linuxbrew,muellermartin/dist,vitorgalvao/brew,rwhogg/brew,aw1621107/brew,reelsense/brew,zmwangx/brew,maxim-belkin/brew,pseudocody/brew,sjackman/homebrew,DomT4/brew,pseudocody/brew,ilovezfs/brew,JCount/brew,gregory-nisbet/brew,vitorgalvao/brew,reelsense/brew,claui/brew