Added symbolic link "aerospike" to current directory.

This makes it possible to use:
```go
import "github.com/aerospike/aerospike-client-go/aerospike"
```
as required by some Go-IDEs (among which IntelliJ) - the package name should be the same as the directory name they are in (according to those IDEs)

This way, we still follow the Go-guidelines at: https://golang.org/doc/code.html#Workspaces
I quote: "src contains Go source files organized into packages (one package per directory)"

According to the Godoc documentation, symlinks are completely ignored as to the godoc.org webpage, so no issues there.