Fix Docker file not including build essential (#346)
Fix Docker file not including build essential (#346)

Signed-off-by: Li Tai <9f2d6e1f0317c3d8d6e8881c5bf72150fc9ba488@pivotal.io>
pivotal/LicenseFinder,bdshroyer/LicenseFinder,sschuberth/LicenseFinder,bdshroyer/LicenseFinder,sschuberth/LicenseFinder,bdshroyer/LicenseFinder,pivotal/LicenseFinder,sschuberth/LicenseFinder,pivotal/LicenseFinder,bdshroyer/LicenseFinder,bdshroyer/LicenseFinder,sschuberth/LicenseFinder,pivotal/LicenseFinder,pivotal/LicenseFinder,sschuberth/LicenseFinder,pivotal/LicenseFinder,pivotal/LicenseFinder