[mscclpp-test] Add AllToAll tests

[Binyang2014]

For 1n-8p

#
# Initializing MSCCL++
# Setting up the connection in MSCCL++
#
#                                    in-place                       out-of-place          
#       size         count     time   algbw   busbw  #wrong     time   algbw   busbw  #wrong
#        (B)    (elements)     (us)  (GB/s)  (GB/s)            (us)  (GB/s)  (GB/s)       
  1073741824      33554432                                    7186.2  149.42  130.74      0

# Out of bounds values : 0 OK
#

For 2n-8p

[1,0]<stdout>:# Initializing MSCCL++
[1,0]<stdout>:# Setting up the connection in MSCCL++
[1,0]<stdout>:#
[1,0]<stdout>:#                                    in-place                       out-of-place          
[1,0]<stdout>:#       size         count     time   algbw   busbw  #wrong     time   algbw   busbw  #wrong
[1,0]<stdout>:#        (B)    (elements)     (us)  (GB/s)  (GB/s)            (us)  (GB/s)  (GB/s)       
[1,0]<stdout>:  1073741824      16777216                                     23275   46.13   43.25      0
[1,0]<stdout>:
[1,0]<stdout>:# Out of bounds values : 0 OK

For kernel 1
1n-8p

[1,0]<stdout>:# Initializing MSCCL++
[1,0]<stdout>:# Setting up the connection in MSCCL++
[1,0]<stdout>:#
[1,0]<stdout>:#                                    in-place                       out-of-place          
[1,0]<stdout>:#       size         count     time   algbw   busbw  #wrong     time   algbw   busbw  #wrong
[1,0]<stdout>:#        (B)    (elements)     (us)  (GB/s)  (GB/s)            (us)  (GB/s)  (GB/s)       
[1,0]<stdout>:  1073741824      33554432                                    4111.8  261.14  228.50      0
[1,0]<stdout>:
[1,0]<stdout>:# Out of bounds values : 0 OK
[1,0]<stdout>:#

[chhwang]

Looks good