PARQUET-1162: Update dev/README after migration to Gitbox

Author: Uwe L. Korn <uwe@apache.org>

Closes #417 from xhochy/PARQUET-1162 and squashes the following commits:

f0c1a3b [Uwe L. Korn] PARQUET-1162: Update dev/README after migration to Gitbox

dev/README.md

diff --git a/dev/README.md b/dev/README.md
index 47a6d46..d567672 100644
--- a/dev/README.md
+++ b/dev/README.md
@@ -21,8 +21,8 @@
 * How to merge a Pull request:
 have an apache and apache-github remote setup
 ```
-git remote add apache-github git@github.com:apache/parquet-cpp.git
-git remote add apache https://git-wip-us.apache.org/repos/asf/parquet-cpp.git
+git remote add apache-github https://github.com/apache/parquet-cpp.git
+git remote add apache git@github.com:apache/parquet-cpp.git
 ```
 run the following command
 ```

dev/committers-guide.md

diff --git a/dev/committers-guide.md b/dev/committers-guide.md
index 9c15071..f3fddfd 100644
--- a/dev/committers-guide.md
+++ b/dev/committers-guide.md
@@ -45,7 +45,7 @@
 
 2. Add your gpg key to the Apache Parquet {format,mr,cpp} KEYS file:
 
-               git clone https://git-wip-us.apache.org/repos/asf/parquet-{format,mr,cpp}.git
+               git clone git@github.com:apache/parquet-cpp.git
                (gpg --list-sigs <KEY ID> && gpg --armor --export <KEY ID>) >> KEYS
                git add KEYS && git commit -m "Adding gpg key for <APACHE ID>"
                ./rbt post -o -g