Turns Rule 304 from Erorr into Warning (#149)

* Update rule 304 to warning.

* remove git ignore.

pom.xml

@@ -3,7 +3,7 @@
 	<groupId>edu.iris.dmc</groupId>
 	<artifactId>stationxml-validator</artifactId>
 	<packaging>jar</packaging>
-	<version>1.7.4</version>
+	<version>1.7.5</version>
 	<name>FDSN StationXML Validator</name>
     <url>http://maven.apache.org</url>
     <description>Converts seismological metadata between dataless seed and FDSN StationXML file formats.</description>

src/main/java/edu/iris/dmc/station/conditions/SensorCondition.java

@@ -30,12 +30,12 @@ public Message evaluate(Channel channel) {
 		}
 
 		Equipment equipment = channel.getSensor();
-		if (this.required) {
+        if (this.required) {
 			if (equipment == null) {
-				return Result.error("expected equipment/sensor but was null");
+				return Result.warning("expected equipment/sensor but was null");
 			}else{
 				if (equipment.getDescription() == null||equipment.getDescription().trim().isEmpty()) {
-					return Result.error("expected equipment/sensor description but was null");
+					return Result.warning("expected equipment/sensor description but was null");
 				}
 			}
 		}

src/test/java/edu/iris/dmc/station/conditions/Condition304Test.java

@@ -36,7 +36,9 @@ public void fail() throws Exception {
 			SensorCondition condition = new SensorCondition(true, "");
 
 			Message result = condition.evaluate(c);
-			assertTrue(result instanceof edu.iris.dmc.station.rules.Error);
+
+		    System.out.print(result);
+			assertTrue(result instanceof edu.iris.dmc.station.rules.Warning);
 		}
 
 	}

src/test/java/edu/iris/dmc/station/conditions/SensorCondition304Test.java

@@ -36,7 +36,7 @@ public void fail() throws Exception {
 			SensorCondition condition = new SensorCondition(true, "");
 
 			Message result = condition.evaluate(c);
-			assertTrue(result instanceof edu.iris.dmc.station.rules.Error);
+			assertTrue(result instanceof edu.iris.dmc.station.rules.Warning);
 		}
 
 	}