Fix/#116 fail to validate numeric (#117)

* Fixed validators for path parameter and query parameter
The following schema can work properly now
- minimum
- maximum
- enum
- pattern
- maxItems
- minItems

* - Change method name in EnumValidator from isTypeLooseEqual to isTypeLooseContainsInEnum and add comments to it, in addition, typeLoose check is been taken out from the method.
- Reconstruct the isNumber check, now all the type check will be done by typeValidator, and minimumValidator and maximumValidator will reuse the isNumber() method provided by typeValidator.
- Add typeLoose config into JsonSchemaTest and adding test cases in enum, minimum and maximum.

* - Added more test cases in enum test

* Fix #116 fail to validate numeric and integer in TypeValidator

Author: jiachen1120

src/main/java/com/networknt/schema/TypeValidator.java

@@ -99,14 +99,11 @@ public Set<ValidationMessage> validate(JsonNode node, JsonNode rootNode, String
     }
 
     public static boolean isInteger(String str) {
-        if (str == null) {
-            return false;
-        }
-        if (str.isEmpty()) {
+        if (str == null || str.equals("")) {
             return false;
         }
         int i = 0;
-        if (str.charAt(0) == '-') {
+        if (str.charAt(0) == '-' || str.charAt(0) == '+') {
             if (str.length() == 1) {
                 return false;
             }
@@ -126,24 +123,30 @@ public static boolean isBoolean(String s) {
     }
 
     public static boolean isNumeric(String str) {
-        if (str == null) {
-            return false;
-        }
-        if (str.isEmpty()) {
+        if (str == null || str.equals("")) {
             return false;
         }
         int i = 0;
-        if (str.charAt(0) == '-') {
+        boolean hasDot = false;
+        if (str.charAt(0) == '-' || str.charAt(0) == '+') {
             if (str.length() == 1) {
                 return false;
             }
             i = 1;
         }
         for (; i < str.length(); i++) {
             char c = str.charAt(i);
-            if (c < '0' || c > '9' && c != '.') {
+            if ((c < '0' || c > '9') && c != '.') {
                 return false;
             }
+            if (c == '.') {
+                if (hasDot) {
+                    return false;
+                }
+                else {
+                    hasDot = true;
+                }
+            }
         }
         return true;
     }