install realpath for ubuntu

.travis.yml

@@ -3,7 +3,7 @@ language: cpp
 sudo: required
 
 install:
-    - sudo apt-get install -qq libgflags-dev libprotobuf-dev libprotoc-dev protobuf-compiler libleveldb-dev
+    - sudo apt-get install -qq realpath libgflags-dev libprotobuf-dev libprotoc-dev protobuf-compiler libleveldb-dev
     - sh config_brpc.sh --headers=/usr/include --libs=/usr/lib
     - make -sj8
 

docs/cn/getting_started.md

@@ -13,7 +13,7 @@ brpc depends on following packages:
 
 Install common deps:
 ```
-$ sudo apt-get install git g++ make libssl-dev
+$ sudo apt-get install git g++ make libssl-dev realpath
 ```
 
 Install [gflags](https://github.com/gflags/gflags), [protobuf](https://github.com/google/protobuf), [leveldb](https://github.com/google/leveldb):