refactoring queue class
refactoring stack class
refactoring Hashtable tests
solved conflicts
added all exception in \System namespace
Merge branch 'feature/add-exceptions' into corelib
introduce composer
refactored tests
changed some tests in TimeSpanFixture
added travis
solved travis issues
refactoring in MathFixture
refactored ObjectFixture
refactored RandomFixture
refactored TimeSpanFixture
changed DateTimeTestCase
renamed test cases
changed StringTestCase
added fromBase64String method
created fromBase64CharArray in \System\CoConvert