iperf: Add version 3.1.3

Description [1]:

> iPerf3 is a tool for active measurements of the maximum achievable
> bandwidth on IP networks. It supports tuning of various parameters
> related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and
> IPv6). For each test it reports the bandwidth, loss, and other
> parameters. This is a new implementation that shares no code with the
> original iPerf and also is not backwards compatible. iPerf was
> orginally developed by NLANR/DAST. iPerf3 is principally developed by
> ESnet / Lawrence Berkeley National Laboratory. It is released under a
> three-clause BSD license.

Create the bee file with the command below, and convert it to a
versionless bee file.

```
$ bee init https://iperf.fr/download/source/iperf-3.1.3-source.tar.gz
creating iperf-3.1.3-0.bee from template '/etc/default/bee/templates/fallback'
```

Disable building of static variants of the library.

[1] https://iperf.fr/

iperf.be0

@@ -0,0 +1,86 @@
+#!/usr/bin/env beesh
+
+# BEE_VERSION iperf-3.1.3-0
+
+## this file was created by bee init and should be executed to build a
+## bee-package. (Additional hints are located at the end of this file.)
+
+###############################################################################
+## The source URL(s) define the location of the sources that will be
+## downloaded. Version variables may be used to simplify reuse of this bee-file.
+
+SRCURL[0]="https://iperf.fr/download/source/iperf-${PKGVERSION}-source.tar.gz"
+
+###############################################################################
+## Add URLs/pathes to patch files to the PATCHURL array.
+## The sources will be patched in the order of the array.
+
+# PATCHURL+=()
+
+###############################################################################
+## Add filename patterns to the EXCLUDE array of files that should not
+## be added to you package but may be present in the image directory.
+
+# EXCLUDE+=()
+
+###############################################################################
+## Uncomment the next statement, if the software may not be able to be built
+## outside the source directory and needs to be built inside the source
+## directory.
+
+# build_in_sourcedir
+
+###############################################################################
+## bee cannot detect buildtypes specified in subdirectories.
+## Sometimes packages "hide" the real sources in a subdirectory named
+## 'src' or 'cmake' or ..
+## use 'sourcesubdir_append' to specify this directory if known.
+
+# sourcesubdir_append src
+
+
+###############################################################################
+## Change the default (auto-detected) steps to
+## extract, patch, configure/setup, build and install the software.
+## Make sure the mee_install function does install everything to the
+## image directory "${D}"
+
+#mee_extract() {
+#    bee_extract "${@}"
+#}
+
+#mee_patch() {
+#    bee_patch "${@}"
+#}
+
+mee_configure() {
+    bee_configure \
+        --disable-static
+}
+
+#mee_build() {
+#    bee_build
+#}
+
+#mee_install() {
+#    bee_install
+#}
+## by default this may be 'make install DESTDIR="${D}"'
+
+###############################################################################
+##
+## Additional hints:
+##
+## The name of this bee-file should follow the following naming convention:
+##     pkgname-pkgversion-pkgrevision.bee
+##
+## You may remove all comments as long as SRCURL[0] is set.
+##
+## Everything in this file will be executed in a bash environment.
+##
+## Build the package by executing
+##     './pkg-version-N.bee' or
+##     'beesh ./pkg-version-N.bee'
+##
+## see http://beezinga.org/
+##