Swap Laravel Package

• Migrated from PHP 5.5 to PHP 7.1+
• Updated PHP HTTP dependency to version 2
• Removed the deprecated Yahoo service which has been removed by Yahoo
• Removed the deprecated Google service which has been very unreliable and unstable on different platforms
• Fixed the exchange rate value to always be a float instead of a string
• Added information about which service returned a rate with ExchangeRate::getProviderName()
• Removed the InternalException only used in the PhpArray service
• Modified the PHPArray service to only support scalars as rates (rate objects are not compatible)
• We now rely on PSR-16 Simple Cache instead of PSR-6 Cache. You can use https://github.com/php-cache/simple-cache-bridge as a bridge between PSR-6 and PSR-16.
• Added a getCurrencyPair() to the exchange rate objects
• Removed the Historical service class in favor of the SupportsHistoricalQueries trait

This log contains the important changes for the 3.x versions.

• Added CurrencyConverterApi service

• Fixed Fixer service which now requires an access_key

• Added Forge service

• Added CurrencyDataFeed service

• Supported historical rates in National Bank Of Romania

• Support crypto currencies via Cryptonator

• New Russian Central Bank service

• e5234ea Added a .gitattributes file

• 24ba8f3 Use Httplug instead of egeloen

• 638255b PSR Cache implementation

• 80abb02 Add documentation about caching

• acd8eb6 Removed currency codes enumeration

• b0a8aba Added interfaces for CurrencyPair and Rate

• eefb252 Removed unused InvalidCurrencyCodeException

• 457a72a New Swap

• 02f0b66 Updated the documentation

• 55ab175 Rely on Exchanger 0.1

• 92a7d2c Updated README

• feb6102 Added a CHANGELOG file