Remove dot in account name when building the permlink for comments

[oroger]

Hello This is my first contribution to SteemJ, small one.

We are using SteemJ for SteemitWorldMap. We recently found out that autocomment are failing on user contaning a dot in the account name.

This issue is that the generated permlink for the reply also contains a dot character, rendering it invalid by the permlink validator.

Form what I see in the condenser interface, it is removing the dot character. I implemented the same behavior in this PR. This should be the only character to removing since account names can only contain alphanumerical characters + dot.

Here is a simple test to reproduce the issue :

	@Test
	public void comment() throws Exception {
		new SteemJ().createComment(new AccountName("malik.roxane"), new Permlink("colorchallenge-make-it-like-a-sunflower"), "SteemJ test", new String[]{ "test", "steemj" });
	}

As you can see here, applying this pull request fixes the issue and allows the comment as expected.

[marvin-we]

Hay @oroger and thank you for using SteemJ to realize your project =)

I really appreciate your PullRequest <3 As a tip: You may want to get rewarded for this using https://utopian.io which is also sponsored a little bit by SteemJ 👍

Best regards!