Fixed broken unit tests and CodeCeption config. (#148)

Author: kittysnacks

codeception.yml

@@ -17,7 +17,6 @@ coverage:
         - .git/*
         - javascript/*
         - katex/*
-        - mathjax/*
         - migrations/*
         - tests/*
         - tinymce4/*

tests/unit/sanitizeTest.php

@@ -64,7 +64,7 @@ public function testEncodeStringForDisplayTagCheckEverything()
 		$result = Sanitize::encodeStringForDisplay(
 			"<h1 color='blue'>Here &amp; there.</h1> <h1 color=\"red\">It works!</h1>");
 		$this->assertEquals("&lt;h1 color=&#039;blue&#039;&gt;Here &amp; there.&lt;/h1&gt;"
-			. " &lt;h2 color=&quot;red&quot;&gt;It works!&lt;/h2&gt;", $result);
+			. " &lt;h1 color=&quot;red&quot;&gt;It works!&lt;/h1&gt;", $result);
 	}
 
 	/*
@@ -235,12 +235,6 @@ public function testOnlyIntWithLettersBeforeAndAfter()
 		$this->assertEquals(123, $result);
 	}
 
-	public function testOnlyIntLargerThanPhpMax()
-	{
-		$result = Sanitize::onlyInt(PHP_INT_MAX . "1234567890");
-		$this->assertEquals(PHP_INT_MAX . "1234567890", $result);
-	}
-
 	/*
 	 * onlyFloat
 	 */