Add regex to get error code from bandit output

This fix modifies the regex to search for the bandit error code.
The bandit error code always begins with 'B' followed by a 3 digit
number.

This will effectively make Sublimelinter-bandit consistent with
other plugins like Sublimelinter-pylint that show an error code.

For example, pylint plugin shows as:
     1:1    warning       pylint: C0111        Missing module docstring (missing-docstring)

Whereas the bandit plugin currently shows as:
    21:1    warning       bandit: Medium       Use of insecure MD2, MD4, or MD5 hash function.

After this fix is merged, it will display as:
    21:1    warning       bandit: B303         Use of insecure MD2, MD4, or MD5 hash function.

Signed-off-by: Eric Brown <[email protected]>

Author: ericwb

linter.py

@@ -23,7 +23,7 @@ class Bandit(PythonLinter):
     version_re = r'^bandit\s(?P<version>\d+.\d+.\d+)'
     version_requirement = '>= 1.3.0'
     regex = (
-        r'^>>\sIssue:\s\[.+\]\s(?P<message>.+)$\r?\n'
+        r'^>>\sIssue:\s\[(?P<code>[B]\d+):.+\]\s(?P<message>.+)$\r?\n'
         r'^.*Severity:\s(?:(?P<error>High)|(?P<warning>(Medium|Low))).*$\r?\n'
         r'^.*Location:.*:(?P<line>\d+)$\r?\n'
     )