Update supported Ruby version

Author: rastating

.ruby-version

@@ -1 +1 @@
-2.2.6
+2.4.1

.travis.yml

@@ -1,8 +1,7 @@
 language: ruby
 rvm:
-  - 2.2.6
-  - 2.3.3
-  - 2.4.0
+  - 2.3.4
+  - 2.4.1
 before_install:
   - "echo 'gem: --no-ri --no-rdoc' > ~/.gemrc"
 script: bundle exec rspec

README.md

@@ -4,7 +4,7 @@
 A Ruby framework for developing and using modules which aid in the penetration testing of WordPress powered websites and systems.
 
 ### What do I need to run it?
-Ensure that you have Ruby >= 2.2.6 installed on your system and then install all required dependencies by opening a command prompt / terminal in the WPXF folder and running ```bundle install```.
+Ensure that you have Ruby >= 2.4.1 installed on your system and then install all required dependencies by opening a command prompt / terminal in the WPXF folder and running ```bundle install```.
 
 If bundler is not present on your system, you can install it by running ```gem install bundler```.