Adding string.h for strdup()
Adding string.h for strdup()

jakubskopal/node-execpe,jakubskopal/node-execpe,coleww/node-kexec,foysavas/node-kexec,jprichardson/node-kexec,coleww/node-kexec,foysavas/node-kexec,jprichardson/node-kexec,jakubskopal/node-execpe,coleww/node-kexec,foysavas/node-kexec,jprichardson/node-kexec