feat: raise errors when versions are not supported

There were scenarios where an upgrade was not compatible because of
peerDependencies not being valid.  This caused the version to be
upgraded to a lower version than what we intended.  Instead
of allowing that to happen, we will now raise an error that communicates
why we were not able to upgrade to the newer version.

deploy/lib/deployer/errors.rb

@@ -43,4 +43,16 @@ class FailedToCreatePRError < BaseError
 
   class AutoMergeFailure < BaseError
   end
+
+  class RequirementsNotMet < BaseError
+    def initialize(version)
+      super(build_message(version))
+    end
+
+    def build_message(version)
+      "Upgrade does not satisfy requirements. The latest upgradable verison is #{version}. " \
+        "Verify that the requirement allows for an upgrade to this version and check that all " \
+        "peer dependencies are satisfied."
+    end
+  end
 end

deploy/lib/deployer/repo/dependabot_pull_request_updater.rb

@@ -5,6 +5,7 @@ class Repo
     class DependabotPullRequestUpdater < PullRequestUpdater
       def run
         setup_runner
+        verify_upgrade_satisfies
         create_pr
         automerge_pr if config.automerge
       end
@@ -198,6 +199,18 @@ def sanitize_yarnrc_yml(fetcher)
         yarnrc_yml_file.content =
           yarnrc_yml_file.content.gsub("yarnPath:", "# yarnPath:")
       end
+
+      def verify_upgrade_satisfies
+        if Gem::Version.new(resolvable_version) >= Gem::Version.new(version)
+          return
+        end
+
+        raise RequirementsNotMet, resolvable_version
+      end
+
+      def resolvable_version
+        checker.latest_resolvable_version
+      end
     end
   end
 end