Fix go test

Author: tetsuok

README.md

@@ -21,7 +21,6 @@ Build Instructions
 
 ### Testing ###
 
-    $ export GOPATH=$(pwd)
     $ go test github.com/tetsuok/go-pegasos/pegasos
 
 If you want to run testing including benchmarks, use `check.sh`

check.sh

@@ -4,7 +4,6 @@
 # license that can be found in the LICENSE file.
 
 set -x
-export GOPATH=$(pwd)
 
 # Just testing.
 # go test -test.v -test.parallel 4 github.com/tetsuok/go-pegasos/pegasos