Merge pull request lancaster-university#9 from microbit-foundation/bu…

…ild-py-fix-t-help

build.py: Fix option description for the `-t/test_platform` option

build.py

@@ -33,7 +33,7 @@
 
 parser = optparse.OptionParser(usage="usage: %prog target-name-or-url [options]", description="This script manages the build system for a codal device. Passing a target-name generates a codal.json for that devices, to list all devices available specify the target-name as 'ls'.")
 parser.add_option('-c', '--clean', dest='clean', action="store_true", help='Whether to clean before building. Applicable only to unix based builds.', default=False)
-parser.add_option('-t', '--test-platforms', dest='test_platform', action="store_true", help='Whether to clean before building. Applicable only to unix based builds.', default=False)
+parser.add_option('-t', '--test-platforms', dest='test_platform', action="store_true", help='Specify whether the target platform is a test platform or not.', default=False)
 parser.add_option('-l', '--lock', dest='lock_target', action="store_true", help='Create target-lock.json, updating patch version', default=False)
 parser.add_option('-b', '--branch', dest='branch', action="store_true", help='With -l, use vX.X.X-BRANCH.Y', default=False)
 parser.add_option('-m', '--minor', dest='update_minor', action="store_true", help='With -l, update minor version', default=False)