fix format.sh to not format nlopt.h

format.sh

 #!/bin/bash
-ls *.cpp *.h | grep -Ev "^(blas[.]h|lapack[.]h|nlopt[.h])$" | xargs clang-format-3.6 -i
+ls *.cpp *.h | grep -Ev "^(blas[.]h|lapack[.]h|nlopt[.]h)$" | xargs clang-format-3.6 -i