Add releases back into timeline

[Xetnus]

Fixes #419 by:

1. Creating a link between the Release and Project models
2. Adding an API endpoint (/api/projects/1/releases) to get the releases for a particular project
3. Using that endpoint to load in the releases and events for a vulnerability in parallel
4. Merging releases and normal events into one global array, but still distinguishing between releases and normal events when necessary, like when clicking on the chics/ticks
5. Moving the zoom and reset buttons down below the timeline
6. Adding unit tests for the release model

[coveralls]

Pull Request Test Coverage Report for Build 1358

• 31 of 36 (86.11%) changed or added relevant lines in 6 files are covered.
• 23 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.3%) to 88.59%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
app/controllers/projects_controller.rb	7	12	58.33%

Files with Coverage Reduction	New Missed Lines	%
app/controllers/filepaths_controller.rb	3	37.93%
lib/event_generators/weekly_report_events.rb	20	26.44%

Totals
Change from base Build 959:	-0.3%
Covered Lines:	1382
Relevant Lines:	1560

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💛 - Coveralls

[Xetnus]

Based on our discussion last Thursday, I'm going to create a new section of buttons below and to the right of the horizontal timeline that would hold the Zoom Level button and Reset button. This means that those buttons would be moved down from where they are now.