Updated README.

Included sentence on opam config env, and running a test binary.

bindings/ocaml/README

@@ -12,7 +12,8 @@ correct location. The default location is
 
 To Build:
 
-1. Install opam
+1. Install opam. Make sure to run eval `opam config env` to make sure
+   environment variables are set properly. 
 
 2. Install necessary packages:
 
@@ -20,6 +21,8 @@ To Build:
 
 4. Run make
 
+5. Test the bindings by running ./test-bindings.native
+
 To rebuild the build files (make, configure etc) run oasis setup
 
 To install the bindings run make install