Package fr3_impedance_controller_real in nix env

Including all deps. Tested with nix develop then roslaunch franka_example_controllers ....

Issue with libfranka version, in the end needed to use fetchGithub in Nix to get proper files.

Closes #7 (closed)

common/include/utilities/Timer.hpp

+/*! @file  Timer.hpp
+ *  @brief Timer for measuring how long things take
+ */
+
+#ifndef TIMER_HPP_
+#define TIMER_HPP_
+
+#include <assert.h>
+#include <stdint.h>
+#include <time.h>
+
+class Timer
+{
+private:
+  struct timespec start_time_;
+
+public:
+  /*!
+   * Construct and start timer
+   */
+  explicit Timer()
+  {
+    start();
+  };
+
+  /*!
+   * Start the timer
+   */
+  void start()
+  {
+    clock_gettime(CLOCK_MONOTONIC, &start_time_);
+  }
+
+  /*!
+   * Get milliseconds elapsed
+   */
+  double getMillisec()
+  {
+    return (double)getNanosec() / 1.e6;
+  }
+
+  /*!
+   *Get nanoseconds elapsed
+   */
+  int64_t getNanosec()
+  {
+    struct timespec now;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    return (int64_t)(now.tv_nsec - start_time_.tv_nsec) +
+      1'000'000'000 * (now.tv_sec - start_time_.tv_sec);
+  }
+
+  /*!
+   * Get seconds elapsed
+   */
+  double getSeconds()
+  {
+    return (double)getNanosec() / 1.e9;
+  }
+};
+
+#endif  // TIMER_HPP_
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