Return nil on .which if processor isn't found, don't rely on string length
Install graphicsmagick on Travis
Merge pull request #193 from minimagick/fix_192

Return nil on .which if processor isn't found, don't rely on string length
Calling specific builder functions depending upon the tool for common verbs, to fix #191
Merge pull request #196 from tinygrasshopper/dev/tinygrasshopper/bug/191

Fixing the builder for verbs which are common between mogrify and image creator
Consider Pathname object as String, rather than stream when MiniMagick::Image#write
Merge pull request #199 from Slacken/write_to_pathname

Consider Pathname object as String, rather than stream when MiniMagick::Image#write
Add docs badge to README
Add spec that we get a reasonable error message when ImageMagick and GraphicsMagick are both unavailable.  This is an issue with v3.7.0 that was (accidentally?) fixed in commit 2f6f7a1, and I would like it to stay fixed.  The previous error message was "undefined method `size' for nil:NilClass", which is not very helpful, while the current one says "No such file or directory - identify".
Allow both 'No such file' and 'not found' in the error message to support various versions of Ruby
Merge pull request #201 from pdg137/master

Add spec that we get a reasonable error message when ImageMagick is not found
Merge pull request #200 from rrrene/patch-1

Add docs badge to README
Add MiniMagick.validate_on_create and MiniMagick.validate_on_write flags

Disabling these flags can save lots of CPU time especially when used in `carrierwave` uploaders with multiple processings
Merge pull request #205 from andreychernih/optional-validation

Add MiniMagick.validate_on_create and MiniMagick.validate_on_write flags
Fixed extracting layers from image

Before it threw an exception because #{filename}.#{newformat} didn't
exist, but when extracting layers we should check for #{filename}-0.#{newformat}.
Rubocop cleanup.
Lazily loading the image info - Instead of re-calling the command line on every info check.
Updated ignores.
Update travis-ci link and icon
Updated code climate link and badge