Hide install via pip prompt, since 0.3 has not been published (#287)

README.md

@@ -21,12 +21,6 @@ The tool dispatches and runs trial jobs that generated by tuning algorithms to s
 
 ## **Install & Verify**
 
-**Install through pip** 
-* We only support Linux in current stage, Ubuntu 16.04 or higher are tested and supported. Simply run the following `pip install` in an environment that has `python >= 3.5`.
-```bash
-    python3 -m pip install --user nni-pkg
-```
-
 **Install through source code**
 * We only support Linux in current stage, Ubuntu 16.04 or higher are tested and supported. Simply run the following `pip install` in an environment that has `python >= 3.5`, `git` and `wget`.
 ```bash