Add support for --fail-under flag

Add a --fail-under <score> flag, also configurable in a `.pylintrc`file

If the final score is more than the specified score, it's considered a
success and pylint exits with exit code 0. Otherwise, it's considered
a failure and pylint exits with its current exit code based on the
messages issued.

Close #2242

2 files changed, 24 insertions, 0 deletions

diff --git a/tests/input/fail_under_minus6.py b/tests/input/fail_under_minus6.py
new file mode 100644
index 000000000..7984ffd1b
--- /dev/null
+++ b/tests/input/fail_under_minus6.py
@@ -0,0 +1,16 @@
+"""
+	Pylint score:  -6
+"""
+import os
+
+import nonexistent
+
+
+def loop():
+	count = 0
+	for i in range(5):
+		count += 1
+	print(count)
+
+path =   '/tmp'
+os.path.exists(path)
diff --git a/tests/input/fail_under_plus6.py b/tests/input/fail_under_plus6.py
new file mode 100644
index 000000000..640088a3d
--- /dev/null
+++ b/tests/input/fail_under_plus6.py
@@ -0,0 +1,8 @@
+""""
+    pylint score:  +6
+"""
+
+import os
+
+path = '/tmp'
+os.path.exists(path)