tests: merge 'test-push-validation.t' into 'test-push.t'
That test file is very small and is merge with the new 'test-push.t'. No logic
is changed but repository name are update to avoid collision.
We don't register this as a copy because is actually a "ypoc" merging two file
together without replacing the destination and Mercurial cannot express that.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..