Some improvements (#846)

* #833: do not require sudo on TravisCI

* #N/A: Add Python dev releases to TravisCI pipeline

Inspired by Brett Cannon's advise [1].

    1: https://snarky.ca/how-to-use-your-project-travis-to-help-test-python-itself/

* #837: try and kill proc and its children

* #N/A: show shell information on `thefuck --version`

* #N/A: omit default arguments to get_close_matches

* #842: add settings var to control number of close matches

* #N/A: remove `n` from the list of `get_closest`'s args

.github/ISSUE_TEMPLATE.md

@@ -6,11 +6,8 @@ update The Fuck and see if the bug is still there. -->
 if not, just open an issue on [GitHub](https://github.com/nvbn/thefuck) with
 the following basic information: -->
 
-The output of `thefuck --version` (something like `The Fuck 3.1 using Python 3.5.0`):
-
-    FILL THIS IN
-
-Your shell and its version (`bash`, `zsh`, *Windows PowerShell*, etc.):
+The output of `thefuck --version` (something like `The Fuck 3.1 using Python
+3.5.0 and Bash 4.4.12(1)-release`):
 
     FILL THIS IN