Fix for missing 3

Author: henryiii

.travis.yml

@@ -241,7 +241,7 @@ before_install:
   else
     if [ "$PYPY" = "7.3" ]; then
       curl -fSL https://bitbucket.org/pypy/pypy/downloads/pypy2.7-v7.3.1-linux64.tar.bz2 | tar xj
-      PY_CMD=$(echo `pwd`/pypy$PYTHON-v7.3.1-linux64/bin/pypy)
+      PY_CMD=$(echo `pwd`/pypy$PYTHON-v7.3.1-linux64/bin/pypy$PY)
       CMAKE_EXTRA_ARGS+=" -DPYTHON_EXECUTABLE:FILEPATH=$PY_CMD"
     else
       PY_CMD=python$PYTHON