Fix for reports for start and end date

2.0.4

Fix for start date end date issue

Fixed bug in calling summaries from getHoursLoggedFor

FIxed startdate enddate order in calling summaries

No idea how nobody noticed this bug.

Added durations endpoint

• Fixed heartbeats "Missing date" error.
• Added implementation of "durations" method.

Implemented by @rdeanar

Upgraded Guzzle

• Upgraded guzzle from 0.4 to 0.6
• Dropped support for PHP versions 5.4 and 5.5
• Added endpoint resource for Heartbeats
• Changed dailySummary to summaries
• Made code cleaner

URI change for dailySummary to match Wakatime API

Merge pull request #4 from stemsmit/patch-1

URI change for dailySummary to match Wakatime API

Connects the WakaTime stats resource

Merge pull request #3 from chrisvogt/add/api_stats_resource

Connects the WakaTime stats() resource