merge revision(s) ae2a904c,165ddfda,fa7a768f: [Backport #16051]

	Update the certificate files to make the test pass on Debian 10

	The old certificate files (for example, test/rubygems/ca_cert.pem) were
	signed by SHA1.  This message digest is considered too weak and rejected
	by OpenSSL 1.1.1 or later.  Because of this, the test suite does not
	pass on Debian 10.

	https://rubyci.org/logs/rubyci.s3.amazonaws.com/debian/ruby-master/log/20190527T123003Z.fail.html.gz#test%2Frubygems

	This change regenerates the files.
	A shell script for the regeneration (util/create_certs.sh) is also
	added.

	* remove trailing spaces.


	Removed inconsistency file from upstream repository of rubygems.

	  followed up ae2a904c

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_6@67737 b2dd03c8-39d4-4d8f-98ff-823fe69b080e