contrib: remove github-merge.py

This script is a much older copy of the script in
https://github.com/bitcoin-core/bitcoin-maintainer-tools.

Author: fanquake

contrib/README.md

@@ -3,7 +3,6 @@ Repository Tools
 
 ### [Developer tools](/contrib/devtools) ###
 Specific tools for developers working on this repository.
-Contains the script `github-merge.py` for merging github pull requests securely and signing them using GPG.
 
 ### [Verify-Commits](/contrib/verify-commits) ###
 Tool to verify that every merge commit was signed by a developer using the above `github-merge.py` script.

contrib/devtools/README.md

@@ -2,40 +2,6 @@ Contents
 ========
 This directory contains tools for developers working on this repository.
 
-github-merge.py
-===============
-
-A small script to automate merging pull-requests securely and sign them with GPG.
-
-For example:
-
-  ./github-merge.py 3077
-
-(in any git repository) will help you merge pull request #3077 for the
-bitcoin-core/bitcoincore.org repository.
-
-What it does:
-* Fetch master and the pull request.
-* Locally construct a merge commit.
-* Show the diff that merge results in.
-* Ask you to verify the resulting source tree (so you can do a make
-check or whatever).
-* Ask you whether to GPG sign the merge commit.
-* Ask you whether to push the result upstream.
-
-This means that there are no potential race conditions (where a
-pullreq gets updated while you're reviewing it, but before you click
-merge), and when using GPG signatures, that even a compromised github
-couldn't mess with the sources.
-
-Setup
----------
-Configuring the github-merge tool for the bitcoin repository is done in the following way:
-
-    git config githubmerge.repository bitcoin-core/bitcoincore.org
-    git config githubmerge.testcmd "make -j4 check" (adapt to whatever you want to use for testing)
-    git config --global user.signingkey mykeyid (if you want to GPG sign)
-
 people-present.sh
 =================