[CONTRIB] add peak test (#878)

* add peak test

* fix error for lanes=16

* update doc

* fix names

* fix names

python/tvm/exec/measure_peak.py

+"""measure bandwidth and compute peak
+
+e.g.
+python3 -m tvm.exec.measure_peak --target cuda --rpc-host 0.0.0.0 --rpc-port 9090
+python3 -m tvm.exec.measure_peak --target opencl --target-host "llvm -target=aarch64-linux-gnu" \
+        --rpc-host $TVM_OPENCL_DEVICE_HOST --rpc-port 9090
+"""
+
+import argparse
+import logging
+
+from ..contrib.peak import measure_peak_all
+
+def main():
+    """Main funciton"""
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--target', type=str, default="llvm",
+                        help='The build target')
+    parser.add_argument('--target-host', type=str, default=None,
+                        help='The host code compilation target')
+    parser.add_argument('--rpc-host', type=str, default="0.0.0.0",
+                        help='the hostname of the server')
+    parser.add_argument('--rpc-port', type=int, default=9090,
+                        help='The port of the PRC')
+
+    args = parser.parse_args()
+    logging.basicConfig(level=logging.INFO)
+
+    measure_peak_all(args.target, args.target_host, args.rpc_host, args.rpc_port)
+
+if __name__ == "__main__":
+    main()