update pegasus readme
Pegasus is a distributed data-parallel compute engine, use the cyclic dataflow computational model; Users can constructor their own DCG job,
and run the job on their laptop or a distributed environment accross a cluster of computers;
-## Cargo dependency
-### The first way:
-1. Add the public ssh key to you gitlab at profile settings;
-2. Enable ssh-agent, more details in [ssh-agent](https://www.ssh.com/ssh/agent);
-3. Add git dependency in the 'Cargo.toml' :
-
-```toml
-pegasus = { git = "ssh://git@gitlab.alibaba-inc.com/biggraph/Pegasus.git", branch = "develop" }
-```
-### The second way:
-
-1) edit the cargo config file(usually in `~/.cargo/config`), add line:
-
-```
-[net]
-git-fetch-with-cli = true
-```
-2) Add git dependency in the 'Cargo.toml':
-
-```toml
-pegasus = { git = "http://gitlab.alibaba-inc.com/biggraph/Pegasus.git", branch = "develop" }
-```
-
-## Examples(maybe departed)
-
-### K-hop
-
-The `k-hop` is a graph traversal job, which start from a source vertex, and do traversal along edges to get neighbours;
-
-Find source code in [examples/k-hop](http://gitlab.alibaba-inc.com/biggraph/Pegasus/blob/develop/pegasus/examples/k_hop.rs);
-
-#### Run on laptop
-
-You can run with command:
-
-```bash
-cargo run --example k_hop 2 ./graph/resources/data/facebook_combined.txt -w 2
-```
-
-It load a social network graph from facebook: [ego-Facebook](http://snap.stanford.edu/data/ego-Facebook.html);
-
-You can also load your own graph by replace the second parameter after 'k_hop' of to specific another path, make sure the file format is same;
-
-(You can get a binary graph file through [examples/convert](http://gitlab.alibaba-inc.com/biggraph/Pegasus/blob/develop/graph/examples/convert.rs) if the file format is really different);
-
-The program will count 2-hop neighbors for each starting vertices which is sampled from the graph; You can set the `K_HOP_SAMPLES`
-environment variables to change the numbers of starting vertices(default 100) with:
-
-```bash
-export K_HOP_SAMPLES=1000
-```
-
-
-#### Run as service in distributed
-
-You can also run k-hop on a cluster consist of many servers by provide a hosts file, For example, with two servers:
-
-Prepare a 'hostfile' file that specific the addresses of servers, like:
-
-```
-host0:port
-host1:port
-```
-
-And then compile the 'k_hop.rs' to a executable file and dispatch it to all peers;
-```bash
-cargo build --example k_hop --release
-```
-
-After dispatch, on the first server, type in command:
-
-```bash
-./target/release/examples/k_hop 3 ./graph/resources/data/facebook_combined.txt -w 2 -p 0 -n 2 -h hostfile
-```
-
-On the second server, type in command:
-
-```bash
-./target/release/examples/k_hop 3 ./graph/resources/data/facebook_combined.txt -w 2 -p 1 -n 2 -h hostfile
-```
-
-## Other docs:
-[Trace system]( http://gitlab.alibaba-inc.com/biggraph/Pegasus/wikis/Trace_System)
-
-
-
-
-
