1.0.0

• Enhancement: Add Test (#1), by @localheinz
• Enhancement: Add Production (#2), by @localheinz
• Fix: Use dedicated exceptions (#3), by @localheinz
• Fix: Remove unused local variable (#4), by @localheinz
• Fix: Rename namespace (#5), by @localheinz
• Fix: Add opening tags and strict declaration to examples (#6), by @localheinz
• Enhancement: Add FakeVariables (#7), by @localheinz
• Enhancement: Add ReadOnlyVariables (#8), by @localheinz
• Fix: Rename Test to TestVariables (#9), by @localheinz
• Fix: Add DocBlock (#11), by @localheinz
• Fix: DocBlock (#13), by @localheinz
• Enhancement: Throw exception when environment variable could not be set (#14), by @localheinz
• Enhancement: Throw exception when environment variable could not be unset (#15), by @localheinz
• Enhancement: Throw exception when retrieving value of variable that is not set (#16), by @localheinz
• Enhancement: Let TestVariables implement Variables interface (#17), by @localheinz
• Enhancement: Add toArray() to Variables (#18), by @localheinz
• Enhancement: Extract named constructors for FakeVariables (#19), by @localheinz
• Enhancement: Extract named constructors for ReadOnlyVariables (#20), by @localheinz