Add Xcode 6 beta 1 XCTest to framework search path

After installing Xcode 6 Beta 2, `$(DEVELOPER_FRAMEWORKS_DIR)` (i.e.:
`/Applications/Xcode6-Beta2.app/Contents/Developer/Library/Frameworks/`)
no longer contains XCTest.framework.

Add `$(SYSTEM_APPS_DIR)/Xcode6-Beta.app/Contents/Developer/Platforms/{{OSX, iOS}}.platform/Developer/Library/Frameworks`
to frameworks search path in order to allow Quick and Nimble to find the
"old" XCTest.

Fixes issue #50.
Merge pull request #49 from garnett/master

[Nimble] Extend Contain matcher to support String's substring matching
Fixed typo
Updated comment
Added beFalse() matcher
Changed equal() failure message pattern to <expected, got>
Changed exampleGroups() to spec()
Update EqualSpec.swift
Updated for Xcode 6 beta 2
Changed beNil() negative fail message since “expected 'nil' to be non-nil was redundant”
Changed beNil() failure message to <expected, got> pattern
Changed beTrue() fail messages since “expected '0' to be true” was redundant
Changed beFalse() fail messages since “expected '1' to be false” was redundant. Changed references to Game of Thrones.
Merge remote-tracking branch 'origin/master'
Merge pull request #51 from endersstocker/master

[Nimble] Addressed issues #30, 42, 47, 50
Fix failing test