Downgrade Subversion 1.8 to 1.7 in Ubuntu 14.04

I ran into the below problem when I try to update my existing codebase after upgrading the operating system from ubuntu 12.04 to 14.04.

The working copy at '/home/punnadi/wso2/source/platform/turing'
is too old (format 29) to work with client version '1.8.8 (r1568071)' (expects format 31). You need to upgrade the working copy first.

The reason behind this error os Ubuntu 14.04 comes with subversion 1.8.x by default. So I had to downgrade the subversion version to 1.7.x in order to overcome this issue.

I did it with the help of following post (Check the Wauzl's answer).

http://askubuntu.com/questions/453717/i-need-downgrade-from-subversion-1-8-to-subversion-1-7