improve install script
improve install script

cyclaero/cocotron,cneira/cocotron,JackLian/cocotron,crystax/android-vendor-cocotron,yuhangwang/cocotron,ruppmatt/cocotron,ruppmatt/cocotron,guestOS/guestOS,gemu2015/cocotron-sierra,gemu2015/cocotron-sierra,cjwl/cocotron,guestOS/guestOS,cyclaero/cocotron,yuhangwang/cocotron,Suninus/cocotron,cjwl/cocotron,Suninus/cocotron,cneira/cocotron,yuhangwang/cocotron,cyclaero/cocotron,ruppmatt/cocotron,cjwl/cocotron,yuhangwang/cocotron,Suninus/cocotron,cneira/cocotron,cyclaero/cocotron,ruppmatt/cocotron,guestOS/guestOS,JackLian/cocotron,JackLian/cocotron,guestOS/guestOS,cjwl/cocotron,gemu2015/cocotron-sierra,JackLian/cocotron,crystax/android-vendor-cocotron,Suninus/cocotron,gemu2015/cocotron-sierra,crystax/android-vendor-cocotron,cneira/cocotron,crystax/android-vendor-cocotron