Built-in binaries for linux/mac

Closes #17

This will make it a lot easier to get started and you won't have to
worry about conflicting binaries and path issues.

Author: paulcsmith

README.md

@@ -40,7 +40,7 @@ end
 Habitat.raise_if_missing_settings!
 ```
 
-Then install Chromedriver and view the guides: https://luckyframework.org/guides/browser-tests/
+Then view the guides: https://luckyframework.org/guides/browser-tests/
 
 You should be ready to go!
 
@@ -61,4 +61,4 @@ View guide at: https://luckyframework.org/guides/browser-tests/
 
 ## Contributors
 
-* [paulcsmith](https://github.com/paulcsmith) Paul Smith - creator, maintainer
+- [paulcsmith](https://github.com/paulcsmith) Paul Smith - creator, maintainer

src/lucky_flow/chromedriver.cr

@@ -6,36 +6,33 @@ class LuckyFlow::Chromedriver
   getter log_io = IO::Memory.new
 
   private def initialize
-    ensure_chromedriver_is_installed
     @process = start_chromedriver
   end
 
   def self.start
     new
   end
 
-  private def ensure_chromedriver_is_installed
-    if !Process.find_executable("chromedriver")
-      raise <<-ERROR
-      Chromedriver must be available from the command line to use LuckyFlow.
-
-        ▸ On macOS: brew install chromedriver
-        ▸ On Linux: https://makandracards.com/makandra/29465-install-chromedriver-on-linux
-
-      ERROR
-    end
-  end
-
   private def start_chromedriver : Process
     Process.new(
-      "chromedriver",
+      "#{__DIR__}/../../vendor/chromedriver-2.40-#{os}",
       ["--port=4444", "--url-base=/wd/hub"],
       output: log_io,
       error: STDERR,
       shell: true
     )
   end
 
+  private def os
+    {% if flag?(:linux) %}
+      "linux64"
+    {% elsif flag?(:darwin) %}
+      "mac64"
+    {% else %}
+      raise "This OS is not supported yet."
+    {% end %}
+  end
+
   def stop
     process.kill unless process.terminated?
   end