Fix version of slf4j in manifest files

Consistently require 1.7.0. We ship 1.7.2 with our p2 repository but
there is no need to require 1.7.2 since it should be API compatible with
1.7.0.

Change-Id: I8467bb14316cb24daa79e89275332107d2716190
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.test/META-INF/MANIFEST.MF

@@ -60,6 +60,6 @@ Import-Package: com.googlecode.javaewah;version="[1.1.6,2.0.0)",
  org.junit.rules;version="[4.12,5.0.0)",
  org.junit.runner;version="[4.12,5.0.0)",
  org.junit.runners;version="[4.12,5.0.0)",
- org.slf4j;version="[1.7.2,2.0.0)"
+ org.slf4j;version="[1.7.0,2.0.0)"
 Require-Bundle: org.hamcrest.core;bundle-version="[1.1.0,2.0.0)",
  org.hamcrest.library;bundle-version="[1.1.0,2.0.0)"