Increased the minimum IDE version to match results from running the "Usage of IntelliJ API not available in older IDEs" inspection (#164)

Author: jimkyndemeyer

resources/META-INF/plugin.xml

@@ -37,7 +37,7 @@
   </change-notes>
 
   <!-- please see http://www.jetbrains.org/intellij/sdk/docs/basics/getting_started/build_number_ranges.html for description -->
-  <idea-version since-build="172"/>
+  <idea-version since-build="173.2290.1"/>
 
   <!-- please see http://www.jetbrains.org/intellij/sdk/docs/basics/getting_started/plugin_compatibility.html
        on how to target different products -->