Remove PostgreSQL 9.3 support

PostgreSQL 9.3 community support ended in November 2018.

doc/install-requirements.xml

@@ -14,7 +14,7 @@
   </para>
 
   <para>
-   &repmgr; &repmgrversion; is compatible with all PostgreSQL versions from 9.3. See
+   &repmgr; &repmgrversion; is compatible with all PostgreSQL versions from 9.4. See
    section <link linkend="install-compatibility-matrix">&repmgr; compatibility matrix</link>
    for an overview of version compatibility.
   </para>
@@ -115,7 +115,7 @@
 
           <row>
             <entry>
-              &repmgr; 5.x
+              &repmgr; 5.2
             </entry>
             <entry>
               YES
@@ -123,6 +123,21 @@
             <entry>
               <link linkend="release-current">&repmgrversion;</link> (&releasedate;)
             </entry>
+            <entry>
+              9.4, 9.5, 9.6, 10, 11, 12, 13
+            </entry>
+          </row>
+
+          <row>
+            <entry>
+              &repmgr; 5.0, &repmgr; 5.1
+            </entry>
+            <entry>
+              YES
+            </entry>
+            <entry>
+              <link linkend="release-5.1.0">5.1</link> (2020-04-13)
+            </entry>
             <entry>
               9.3, 9.4, 9.5, 9.6, 10, 11, 12
             </entry>
@@ -226,6 +241,9 @@
         <ulink url="https://www.postgresql.org/docs/9.3/release-9-3-25.html">9.3.25</ulink>
         in November 2018) and will no longer be updated with security or bugfixes.
       </para>
+      <para>
+        Beginning with &repmgr; 5.2, &repmgr; no longer supports PostgreSQL 9.3.
+      </para>
       <para>
         PostgreSQL 9.4 has reached the end of its community support period (final release was
         <ulink url="https://www.postgresql.org/docs/9.4/release-9-4-26.html">9.4.26</ulink>