ENH: Make new pytest work (better) and properly support pytest.skip()

This hsould be backwards compatible, but I didn't properly test it.

I realized that version 0.2 existed (but not in the main repo),
so bumping to 0.3 now, although it should be harmless fixes with
no meaningful behavior change.

Author: seberg

README.md

@@ -65,17 +65,20 @@ fail to report, which causes test failures.
 
 The first version effectively ignored the ``--errors-for-leak-kinds`` valgrind
 option. In the current version ``--errors-for-leak-kinds=definite`` will work
-(and ignore "indirect" leaks).
+(and ignore "indirect" leaks), but you must still pass
+``--show-leak-kinds=definite`` it appears.
 
 Any valgrind error or memory leak occuring *during* the test will lead to the
 test being recorded as *FAILURE*. You will have to search the valgrind log
 file for the specific error.
 
-As a further example, one may run an individual NumPy test file with the following
-commend (some of these options are not necessary):
-```
-PYTHONMALLOC=malloc valgrind --show-leak-kinds=definite --log-file=/tmp/valgrind-output python runtests.py -g -t numpy/core/tests/test_dtype.py -- -vv --valgrind --valgrind-log=/tmp/valgrind-output --continue-on-collection-errors
-```
+When running this on a module it makes sense to compile with debug symbols
+usually a ``-g`` option.
+For example to run on NumPy, it is also necessary to use:
+``--continue-on-collection-errors`` since some tests fail during collection
+otherwise.  (This is due to missing support for longdoubles or floating point
+errors.)
+
 
 ### Options
 
@@ -101,6 +104,7 @@ You can mark tests with `pytest.mark.valgrind_known_leak(reason="?!")`
 or `pytest.mark.valgrind_known_error(reason="Oooops")` (or both) to make the test result
 an `xfail` specifically for this plugin and specific to either leaks or other errors
 reported by valgrind.
+These are, however, currently not defined by the plugin (not sure if they should).
 
 Not all errors are necessarily due to your own code, sometimes false positives can be reported
 from known good functions. For example `strcmp` can do this if the valgrind suppressions are not

example/test_example.py

@@ -21,6 +21,9 @@ def test_all_good():
     # This test just passes, yay!
     pass
 
+def test_skipped():
+    # This test is skipped via exception, keep the skip
+    pytest.skip()
 
 def test_fails_but_valgrind_good():
     assert 0
@@ -60,4 +63,4 @@ def test_valgrind_leak_ignored_but_errors_as_well():
 
 def test_another_good_test():
     # Just to show that the old leaks are obviously not still found.
-    pass
+    pass