emc.json: add explicit dependency to Commons Logging 1.2

Installing the JSON EMC driver from Epsilon 2.6 results in a
warning about HttpClient 4 not being able to resolve its dependency
on Apache Commons Logging 1.2. This isn't caught through our usual
plugin dependencies, as HttpClient 4 gets it via Import-Package
so the plug-in installation process doesn't try to fetch it.

plugins/org.eclipse.epsilon.emc.json/META-INF/MANIFEST.MF

@@ -5,11 +5,12 @@ Bundle-SymbolicName: org.eclipse.epsilon.emc.json
 Bundle-Version: 2.7.0.qualifier
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Require-Bundle: org.eclipse.epsilon.eol.engine,
- org.apache.httpcomponents.httpclient,
- org.apache.httpcomponents.httpcore,
+ org.apache.httpcomponents.httpclient;bundle-version="4.0.0",
+ org.apache.httpcomponents.httpcore;bundle-version="4.0.0",
  org.apache.commons.codec,
  com.googlecode.json-simple;bundle-version="1.1.1",
- org.apache.commons.collections;bundle-version="3.2.2"
+ org.apache.commons.collections;bundle-version="3.2.2",
+ org.apache.commons.logging;bundle-version="1.2.0"
 Export-Package: org.eclipse.epsilon.emc.json
 Automatic-Module-Name: org.eclipse.epsilon.emc.json
 Bundle-Vendor: Eclipse Modeling Project