title: Double strip of spaces in string (ruby)
body: <p>I have this string:</p>
  
  <pre><code>"item one :value1 , item2: value2,item3 : value3"
  </code></pre>
  
  <p>how can i  obtain this one?:</p>
  
  <pre><code>"item one:value1,item2:value2,item3:value3"
  </code></pre>
  
  <p>(i need to strip spaces between ","-separated items , and between ":"-separated items)</p>