Simple enums, ternary expressions and other improvements

Resolved issues:

• #33: Transform ternary expression enhancement
• #30: Translate simple enums to Kotlin enhancement
• #24: SwiftKotlinApp changes text selection while writing bug
• #23: Initialize nullable properties to null bug
• #17: Remove -> from lambdas when no parameter enhancement

Support for XCTestCase

Added plugin support, including:

XCTestCase to JUnit plugin:

• Adding @Test, @Before and @Afterannotations, removing calls to super.setUp()and super.tearDown()when applies
• Removing inheritance of `XCTestCase``
• XCTAssertXXX methods to JUnit conterparts, changing parameter order when necessary

SwiftKotlin App Preview

Preview of SwiftKotlinApp using the new transformer based on AST

0.0.1 - Preview

Merge pull request #11 from mikemee/patch-1

Improved phrasing & corrected minor grammar errors