bump to java 1.8

org.eventb.texteditor.parsers/META-INF/MANIFEST.MF

@@ -5,7 +5,7 @@ Bundle-SymbolicName: org.eventb.texteditor.parsers
 Bundle-Version: 3.3.0.qualifier
 Bundle-Activator: org.eventb.texteditor.parsers.Activator
 Require-Bundle: org.eclipse.core.runtime
-Bundle-RequiredExecutionEnvironment: JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Bundle-ClassPath: .,
  lib/guava-14.0.1.jar,
  lib/jsr305-1.3.9.jar,

org.eventb.texteditor.ui/META-INF/MANIFEST.MF

@@ -59,5 +59,5 @@ Export-Package: org.eventb.texteditor.ui;
    org.eclipse.emf.ecore.resource,
    org.eclipse.core.resources,
    org.eclipse.emf.edit.domain"
-Bundle-RequiredExecutionEnvironment: JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Bundle-ActivationPolicy: lazy

org.eventb.texttools/META-INF/MANIFEST.MF

@@ -22,7 +22,7 @@ Require-Bundle: org.eclipse.jface.text;bundle-version="[3.6.0,4.0.0)",
  org.eventb.core;bundle-version="[3.1.0,4.0.0)"
 Bundle-Vendor: Heinrich-Heine University Dusseldorf
 Bundle-ClassPath: .
-Bundle-RequiredExecutionEnvironment: JavaSE-1.7
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Bundle-ActivationPolicy: lazy
 Export-Package: org.eventb.texttools,
  org.eventb.texttools.formulas,