refactor(merchant-sdk): Removed unused code from Session

EC-74

merchant-sdk/sdk/src/main/java/net/gini/android/merchant/sdk/api/authorization/model/Session.kt

@@ -1,6 +1,5 @@
 package net.gini.android.merchant.sdk.api.authorization.model
 
-import net.gini.android.core.api.authorization.apimodels.SessionToken
 import java.util.Date
 
 class Session(
@@ -11,23 +10,4 @@ class Session(
 ) {
     /** The expiration date of the access token.  */
     val expirationDate: Date = Date(expirationDate.time)
-
-    /**
-     * Uses the current locale's time to check whether or not this session has already expired.
-     *
-     * @return Whether or not the session has already expired.
-     */
-    fun hasExpired(): Boolean {
-        val now = Date()
-        return now.after(expirationDate)
-    }
-
-    companion object {
-        fun fromAPIResponse(apiResponse: SessionToken): Session {
-            val accessToken = apiResponse.accessToken
-            val now = Date()
-            val expirationTime = now.time + apiResponse.expiresIn * 1000
-            return Session(accessToken, Date(expirationTime))
-        }
-    }
 }