testify: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/testify - from package: python2-testify

You may install the required package with command yum install {package}

Error in other languages:
testify: bevel nie gevind nie
testify: comandă negăsită
testify: comando não encontrado
testify: commande introuvable
testify: command not found
testify: käsku ei ole
testify: không tìm thấy lệnh
testify: komanda nerasta
testify: Kommando nicht gefunden.
testify: kommandot finns inte
testify: komut yok
testify: nie znaleziono polecenia
testify: níor aimsíodh an t-ordú
testify: no se encontró la orden
testify: no s'ha trobat l'ordre
testify: opdracht niet gevonden
testify: parancs nem található
testify: perintah tidak ditemukan
testify: príkaz nenájdený
testify: příkaz nenalezen
testify: команда не найдена
testify: командата не е открита
testify: 命令找不到
testify: コマンドが見つかりません