Update error messages and test names

src/main/java/com/mattrixwv/cipherstream/monosubstitution/Vigenere.java

@@ -1,4 +1,4 @@
-//CipherStreamJava/src/main/java/com/mattrixwv/CipherStreamJava/monoSubstitution/Vigenere.java
+//CipherStreamJava/src/main/java/com/mattrixwv/cipherstream/monosubstitution/Vigenere.java
 //Matthew Ellison
 // Created: 07-25-21
 //Modified: 05-04-23
@@ -98,7 +98,7 @@ public class Vigenere{
 		setOffset();
 
 		//If after all the eliminating of unusable characters the keyword is empty throw an exception
-		if(this.keyword.isBlank()){
+		if(this.keyword.length() < 2){
 			throw new InvalidKeywordException("Keyword must contain at least 2 letters");
 		}
 	}