Updated Parser to have a public modifier

Author: jrosen081

MathParser.podspec

@@ -31,6 +31,8 @@ MathParser is a pod that parses strings to decimal values. It allows addition, s
   s.ios.deployment_target = '8.0'
 
   s.source_files = 'MathParser/Classes/**/*'
+
+  s.swift_version = '5.0'
 
   # s.resource_bundles = {
   #   'MathParser' => ['MathParser/Assets/*.png']

MathParser/Classes/Source/Parser.swift

@@ -13,7 +13,7 @@ public class Parser {
 	/// Will return nil if the string is not parseable.
 	/// - parameter string: The string to parse
 	/// - returns: An expression that will result in the value
-	static func parse(string: String) -> Expression? {
+	public static func parse(string: String) -> Expression? {
 		let updatedString = Parser.changeMinusIntoOther(change: Operators.subOp, into: string)
 		guard updatedString.contains(Operators.divOp) || updatedString.contains(Operators.multOp) || updatedString.contains(Operators.addOp) || updatedString.contains(Operators.subOp) ||  updatedString.contains(Operators.powOp) || Decimal(string) != nil else {
 			return nil