whitespace stripper for runtime.txt

bin/steps/python

@@ -1,4 +1,8 @@
 set +e
+
+# Fix any pending whitespace around runtime.txt.
+runtime-fixer runtime.txt
+
 PYTHON_VERSION=$(cat runtime.txt)
 
 # Install Python.

vendor/runtime-fixer

@@ -0,0 +1,11 @@
+#!/usr/bin/env python
+
+import sys
+
+runtime_file = sys.argv[1]
+
+with open(req_file, 'r') as f:
+    r = f.read().strip()
+
+with open(runtime_file, 'w') as f:
+    f.write(r)