[swiftlint] Fix violation: operator_whitespace

warning: Operator Function Whitespace Violation: Operators should be surrounded by a single whitespace when defining them.

Apple has also used spacing in The Swift Programming Language book
https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/AdvancedOperators.html#//apple_ref/doc/uid/TP40014097-CH27-ID42

Author: jawwad

QuadTree/Tests/Tests/Tests.swift

@@ -12,7 +12,7 @@ extension Point: Equatable {
 
 }
 
-public func ==(lhs: Point, rhs: Point) -> Bool {
+public func == (lhs: Point, rhs: Point) -> Bool {
   return lhs.x == rhs.x && lhs.y == rhs.y
 }
 

Strassen Matrix Multiplication/StrassensMatrixMultiplication.playground/Sources/Matrix.swift

@@ -19,7 +19,7 @@ public struct Matrix<T: Number> {
   public struct Size: Equatable {
     let rows: Int, columns: Int
 
-    public static func ==(lhs: Size, rhs: Size) -> Bool {
+    public static func == (lhs: Size, rhs: Size) -> Bool {
       return lhs.columns == rhs.columns && lhs.rows == rhs.rows
     }
   }

Strassen Matrix Multiplication/StrassensMatrixMultiplication.playground/Sources/Number.swift

@@ -13,12 +13,12 @@ public protocol Number: Multipliable, Addable {
 }
 
 public protocol Addable {
-  static func +(lhs: Self, rhs: Self) -> Self
-  static func -(lhs: Self, rhs: Self) -> Self
+  static func + (lhs: Self, rhs: Self) -> Self
+  static func - (lhs: Self, rhs: Self) -> Self
 }
 
 public protocol Multipliable {
-  static func *(lhs: Self, rhs: Self) -> Self
+  static func * (lhs: Self, rhs: Self) -> Self
 }
 
 extension Int: Number {

Treap/TreapCollectionType.swift

@@ -85,7 +85,7 @@ extension Treap: MutableCollection {
 
 public struct TreapIndex<Key: Comparable>: Comparable {
 
-  public static func <(lhs: TreapIndex<Key>, rhs: TreapIndex<Key>) -> Bool {
+  public static func < (lhs: TreapIndex<Key>, rhs: TreapIndex<Key>) -> Bool {
     return lhs.keyIndex < rhs.keyIndex
   }