tests: open file in binary mode to use POSIX end-of-line style anywhere
Before this patch, "test-context.py" fails on Windows environment,
because "diff" output contains unexpected "\r" character.
Opening the target file in text mode causes this automatic end-of-line
conversion.
#require test-repo pyflakes
$ cd "`dirname "$TESTDIR"`"
run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)
$ hg locate 'set:**.py or grep("^!#.*python")' 2>/dev/null \
> | xargs pyflakes 2>/dev/null | "$TESTDIR/filterpyflakes.py"
tests/filterpyflakes.py:58: undefined name 'undefinedname'