Improve alt text for logos on About Us page

[carrythebanner]

On the "About us" page (http://calagator.org/about), the "Attributions" section credits a number of logo images. Each image has alt text, but currently it's a mix of a useful label and some random letters and numbers. For example:
<img src="/assets/tag_icons/ruby-6cb4bb736e6c4cb0000f6e4d6254e13d9088263198adc4a1fd0676f8a2f84c34.png" alt="Ruby 6cb4bb736e6c4cb0000f6e4d6254e13d9088263198adc4a1fd0676f8a2f84c34">

Alt text should be human-readable and contextually appropriate. Images will be identified as such by screen readers, so typically alt text should not include the word "image." But in this case since logos are specifically being identified, I'd recommend "Ruby logo" (vs. just "Ruby"), as in:
<%= image_tag "tag_icons/ruby.png" alt: "Ruby logo" %>