updated Swift version file, bumped podspec to 2.1.0, removed swift lint from travis test due to some issue with Xcode 10 and cocoapods

Author: asowers1

.swift-version

@@ -1 +1 @@
-3.0
+4.2

.travis.yml

@@ -22,6 +22,4 @@ script:
   - xcodebuild -project "$PROJECT" -scheme 'SwiftyTimer watchOS' -sdk iphonesimulator -destination 'name=Apple Watch - 42mm' ONLY_ACTIVE_ARCH=NO CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO build | xcpretty
   - xcodebuild -project "$PROJECT" -scheme 'SwiftyTimer OS X' ONLY_ACTIVE_ARCH=NO CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO build | xcpretty
 
-  - pod lib lint
-  
   - xcodebuild -archivePath 'Tests' -project SwiftyTimerTests/SwiftyTimerTests.xcodeproj -scheme 'SwiftyTimerTests' archive && Tests.xcarchive/Products/Applications/SwiftyTimerTests.app/Contents/MacOS/SwiftyTimerTests

SwiftyTimer.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name = 'SwiftyTimer'
-  s.version = '2.0.0'
+  s.version = '2.1.0'
   s.license = 'MIT'
   s.summary = 'Swifty API for NSTimer'
   s.homepage = 'https://github.com/radex/SwiftyTimer'
@@ -14,4 +14,4 @@ Pod::Spec.new do |s|
   s.watchos.deployment_target = '2.0'
 
   s.source_files = 'Sources/*.swift'
-end
+end